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https://www.youtube.com/watch?v=QTfTSh3cekM&feature=youtu.be
GRAFTING TECHNIQUES
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Click here to view the Botany articles contributed by the students in Wikipedia
Click here To view the MUSHROOM CULTIVATION TRAINING PROGRAMME
https://youtu.be/m8n9tEW60Hc
GRAFTING TECHNIQUES
https://www.youtube.com/watch?v=hzBerXm1WCY
LAYERING TECHNIQUES
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Semester - V
ReplyDeleteBotany Paper - V
Title:Cell Biology,Genetics and Plant Breeding
Short Question and Answers for Semester End Exam
Unit - I - Cell Biology
1.What are the differences between Prokaryotic Cell and Eukaryotic Cell?
Ans). Prokaryotic Cell:
i.Nucleus is undefined and the nuclear material is present all over the cell.
ii.Single circular chromosome present.
iii.Plasmid is present which contains extra chromosomal genes which is used in R-DNA technology.
iv.Membrane bound organelles are absent.
v.Genetic material lacks histone proteins.
Eukaryotic Cell:
i.Nucleus is well defined and the nuclear material is bound by a nuclear membrane.
ii.Chromosomal number varies and they are of linear type.
iii.Plasmid is absent.
iv.Membrane bound organelles like mitochondria, chloroplast and etc are present.
v.Genetic material is associated with histone proteins.
2.What are Mesosomes?Mention it's role?
Ans).Mesosomes are the infoldings of the plasma membrane in a prokaryotic cell into the cytoplasm.
Mesosomes main function is respiration in prokaryotic cells.It also helps in the binary fisson and due to the more surface area present near it, many metabolic processes like enzymatic reactions undergo here.
3.What is a Plasmid? Mention it's role in R-DNA technology.
Ans). Plasmid is the extra chromosomal DNA present in a prokaryotic cell which can replicate independently.They are small circular double stranded DNA molecules in bacteria.
The sexual reproduction in bacteria i.e., Conjugation takes place by the transfer of plasmid from a donor cell having a plasmid to a recipient cell lacking a plasmid.
Plasmids play a major role in genetic recombinations in R-DNA technology which are of great use in science, agriculture,medicine and genetics.The desired genes are isolated from the organisms and by the help of vectors(plasmids) genetic recombinations are done in laboratory.
4.Distinguish between Euchromatin and Heterochromatin.
Ans). Euchromatin: The portion in the chromosome which takes less stain and active genes are present and they take part in transcription due to their loose packing.
Heterochromatin:The portion in the chromosome which takes up staining darkly and inactive genes are present.This is due to methylation of the chromatin material and high coiling.
5.What are semi-autonomous cell organelles?Why are they called so?
Ans).The mitochondria and chloroplast are known as the semi-autonomous cell organelles in a plant cell.
They are called as semi-autonomous cell organelles due to their ability to undergo autocatalysis and heterocatalysis.
Autocatalysis is the ability to replicate their own genetic material and heterocatalysis is the synthesis of proteins by transcription and translation.
DEAR REVANTH, GOOD PRESENTATION. USE TWO DIFFERENT COLOURS FOR PRESENTATION. - 1. QUESTIONS 2. ANSWERS
DeleteUnit - II - Genetic Material
ReplyDelete1. Define Nucleoside and Nucleotide.
Ans).Nucleoside:It consists of a sugar molecule attached to a nitogen base.
Nucleotide:It consists of a sugar molecule attached to a nitrogen base and a phosphate group.
2.Give any four differences between DNA and RNA.
Ans). DNA:
i.It is a double stranded molecule acting as univeral genetic material.
ii.DNA contains deoxy ribose sugar molecule in it's structure.
iii.Udergoes autocatalysis and heterocatalysis.
iv.Contains Thymine as one of the nitogen base.
RNA:
i.It is a single stranded molecule which act as a genetic material in the absence of DNA molecule.
ii.RNA contains ribose sugar in it's structure.
iii.Undergoes translation to synthesise protein as a result of transcription by DNA.
iv.Contains Uracil instead of Thymine as nitrogen base.
3.Give details about Watson and Crick.
Ans). Watson and Crick proposed the double helical structure of DNA molecule for which they received a Noble Prize in 1962 under Medicine.
4.Semi-conservative mode of DNA replication?
Ans).Semi-conservative mode of DNA replication was proposed by Watson and Crick in 1953.
They stated that each starnd in the parent DNA act as a template strand and the daughter strands are newly synthesised.The new daughter DNA contain one parental DNA strand and one newly synthesised strand.
5.Give the types of RNA and their functions.
Ans).There are three types of RNA.They are i.m-RNA-It is called messenger-RNA. It is transcribed from the DNA and carries the information for the protein synthesis.
ii.t-RNA-It is called transfer-RNA. It has stem loop structure. It carries amino acids to the site of protein synthesis and has anti-codon site which would be complementary to the mRNA sequence.
iii.r-RNA- It is called ribosomal-RNA. It is the site for the synthesis of proteins. It will help in attachment of the mRNA with the ribosomes.
Unit - III - Mendelian Inheritance
ReplyDelete1. Define law of Dominance.
Ans).Mendel's law stating that when two alleles of an inherited pair is heterozygous, then, the allele that is expressed is dominant whereas the allele that is not expressed is recessive. The expression of the dominant allele suppressing the recessive allele is termed as Law of Dominance.
2.Define Test Cross and Back Cross.
Ans).Test Cross:The cross made between the F1 hybrid with it's recessive parent.It is done to know the homozygosity of the F1 hybrid.
Back Cross:The cross made between the F1 hybrid with any one of the parents.It is done in order to achieve offspring with a genetic identity which is closer to that of the parent.
3.Define Linkage and Crossing Over.
Ans).Linkage:It is the tendency of DNA sequences that are close together on a chromosome to be inherited together during the meiosis phase of sexual reproduction.
Crossing Over:It is the process where 2 homologous chromosome sister chromatids pair up with each other and exchange different segments of genetic material to form 2 recombinant chromosome sister chromatids.
4.Define the second law of Mendelian Inheritance.
Ans).The second law of Mendelian Inheritance is The Law of Independant Assortment of Gametes which states that "When two or more characteristics are inherited, individual hereditary factors assort independently during gamete production, giving different traits an equal opportunity of occurring together."
5.Define Complete Linkage and Incomplete Linkage.
Ans).Complete Linkage: It is defined as the state in which two loci are so close together that alleles of these loci are virtually never separated by crossing over. The closer the physical location of two genes on the DNA, the less likely they are to be separated by a crossing-over event.
Incomplete Linkage:When the genes were loosly linked on a chromosome and show higher percentage of recombination. In such condition non parental type of gametes are formed.
Incomplete linkage produces new combinations of the genes in the progeny due to the formation of chiasma or crossing over in between the linked genes present on homologous chromosomes.
Unit - IV - Plant Breeding
ReplyDelete1.What is Plant Breeding? Give any two objectives.
Ans). Plant breeding is the process by which humans change the characteristics of plants over time to make them better crops and more nourishing food. In its most simple form, breeding consists of selecting the best plants in a given field, growing them to full seed and then using that seed to grow further generations.
Objectives:The main objectives are
i.High Yielding
ii.Disease Resistance
Plant Breeding aims to improve the characteristics of plant so that they become more desirable agronomically and economically. Thus, the chief objective of plant breeding is to develop such improved varieties of crop plants that will be commercially successful.
2.Define Acclimatization.
Ans). Acclimatization is the phenomenom of an intoduced plant to adapt or adjust to the new environmental conditions.
3.Define Introduction and give any two merits.
Ans). Introduction is the earliest of the methods followed in plant breeding. Established plants of one area are taken to the newer area for the use of mankind.
Merits:
i.It is a very quick and economical method of crop improvement.
ii.It may provide an entirely a new crop species. Maize,Potato,tomato are the best examples for introduction.
4.Define Mass, Pureline and Clonal Selection.
Ans). Mass Selection: Selection of a number of phenotypically superior plants heads or seeds from the field population, harvesting and bulking their produce together for sowing the next year’s crop and repeating this process till desired characters are achieved.Mass selection is based on phenotype (external characters).It cannot bring any new change in the genotype. It can be practiced in both self-pollinated and cross-pollinated crops.
Pureline Selection: The process of isolating a desirable homozygous individual from the mixed population and selfing the same without contamination to release as a new variety.It is commonly used to improve the self- pollinated crops.
Clonal Selection:A variety that is propagated vegetative from a single plant is called clone.Selection of desirable clones from the mixed population of vegetative propagated crops is known as clonal selection.
4.Define Hybridization and mention any two objectives.
Ans).Individual produced as a result of cross between two genetically different parents is known as hybrid. The natural or artificial process that results in the formation of hybrid is known as hybridization.
Objectives:
i. To artificially create a variable population for the selection of types with desired combination of characters.
ii.To create high yielding, disease resistant, stress resistant, commercially successful crops.
6.Define emasculation, bagging and tagging.
Ans). Emasculation: The removal or inactivation of male reproductive organs from the selected female parent.
Bagging: The process of covering the selected female flower after artificially pollinating it with the desired pollens.
Tagging: The process of noting down the details related to parents, time of maturation, pollination, place and other details on a card and tying it to the bagged female flower for further reference.
Unit - V - Breeding, Crop Improvement and Biotechnology
ReplyDelete1.Expand RFLP and mention it's objectives.
Ans).RFLP-Restriction Fragment Length Polymorphism
Objectives:
i.Allow the transfer of novel genes from related wild species.
ii.Establish genetic relationships between sexually incompatible crop plants.
2.Define RAPD and mention it's objectives.
Ans). RAPD- Random Amplified Polymorphic DNA
Objectives:
i.RAPD markers are employed in the construction of genetic maps.
ii.RAPD is used to distinguish between variety is based on difference in DNA sequence.
3.Define Somaclonal Variations.
Ans).Somaclonal variation is the variation seen in plants that have been produced by plant tissue culture. Chromosomal rearrangements are an important source of this variation.
Objectives:
i.Somaclonal variation leads to the creation of additional genetic variability.
ii.The major likely benefit of somaclonal variation is plant/crop improvement.
4.Define Molecular Breeding.
Ans).Molecular breeding is defined as a branch of plant breeding which utilizes molecular genetic tools and approaches for genetic improvement of crop plants. In other words, genetic improvement of crop plants for various economic traits using molecular marker and transformation technologies is referred to as molecular plant breeding.
5.What are mutagens?
Ans).Agents with cause mutation in the organism are called mutagens. There are different classes of mutagens based on their chemical or physical properties. All these mutagens induce mutations in the genome by the structural or chemical modification of the genetic material (DNA).
Source: Running Notes and Internet(Wikipedia,Biology Discussion and other websites)
DEAR REVANTH, WRITE YOUR NAME AND NUMBER BEFORE SUBMISSION.
DeleteUnit-1
ReplyDeletePLASMIDS:
A gentic structure in a cell that can replicate independently of the chromosome Typically small circular DNA strands in the cytoplasam of the bacterium.
MESOSOMES:
An organelle of bateria that appears as an invagination of plasma membrane and funtion either in DNA replication and
cell division or excretion of enzyme.
SUICIDAL BAGS:
Lysosomes are called as suicidal bags. They are filled with digestive enzyme. These enzymes also digest any kind of worn out cell organelles or foreign materials bacteria or virus that enter the cell.
NUCLEOSOME MODEL:
A nucleosome is a basic unit of DNA packaging in eukaryotes,consisting of a segment of DNA wound in sequence around eight histone protien cores. This structure often compared to thread wrapped around a pool.
CELL THEORY:
Living organisms are made up of cells.
Cells are basic structural and functional unit of all organisms.
Cells come from pre- existing cells.
WRITE YOUR NAME AND RESUBMIT YOUR ASSIGNMENT.
DeleteWHO PROPOSED THE CELL THEORY?
Unit-1
ReplyDeletePLASMIDS:
A gentic structure in a cell that can replicate independently of the chromosome Typically small circular DNA strands in the cytoplasam of the bacterium.
MESOSOMES:
An organelle of bateria that appears as an invagination of plasma membrane and funtion either in DNA replication and
cell division or excretion of enzyme.
SUICIDAL BAGS:
Lysosomes are called as suicidal bags. They are filled with digestive enzyme. These enzymes also digest any kind of worn out cell organelles or foreign materials bacteria or virus that enter the cell.
NUCLEOSOME MODEL:
A nucleosome is a basic unit of DNA packaging in eukaryotes,consisting of a segment of DNA wound in sequence around eight histone protien cores. This structure often compared to thread wrapped around a pool.
CELL THEORY:
Living organisms are made up of cells.
Cells are basic structural and functional unit of all organisms.
Cells come from pre- existing cells.
Submitted by DB 60
Unit-1
ReplyDeletePLASMIDS:
A gentic structure in a cell that can replicate independently of the chromosome Typically small circular DNA strands in the cytoplasam of the bacterium.
MESOSOMES:
An organelle of bateria that appears as an invagination of plasma membrane and funtion either in DNA replication and
cell division or excretion of enzyme.
SUICIDAL BAGS:
Lysosomes are called as suicidal bags. They are filled with digestive enzyme. These enzymes also digest any kind of worn out cell organelles or foreign materials bacteria or virus that enter the cell.
NUCLEOSOME MODEL:
A nucleosome is a basic unit of DNA packaging in eukaryotes,consisting of a segment of DNA wound in sequence around eight histone protien cores. This structure often compared to thread wrapped around a pool.
CELL THEORY:
Living organisms are made up of cells.
Cells are basic structural and functional unit of all organisms.
Cells come from pre- existing cells.
Submitted by DB 60
Unit - 3
ReplyDeleteMonohybrid cross:
The cross is made b/w 2 induviduals differ in one character.
Dihybrid cross:
The cross is made b/w 2 induviduals differ in two contrasting character.
Test cross:
Cross made b/w F1 hybrid with its recessive parent.
Back cross:
If a cross is made b/w F1 hybrid with any one of its parents.
Linkage:
It is a presence of two or more genes on the chromosomes as a result the genes inherited together more offenly.
Euchromatin:
Light strain
Less condensed
G snd C are more rich.
Heterochromatin:
Dark strain
More condensed
A and T are more.
Crossing over:
An exchange of homologous segments b/w the non sister chromatids.
It occurs during pachytene of meosis- 1
Recombination occurs during crossing over.
WRITE YOUR NAME AND NUMBER
DeleteName: R. Visali
DeleteDB 60
Unit - 3
ReplyDeleteMonohybrid cross:
The cross is made b/w 2 induviduals differ in one character.
Dihybrid cross:
The cross is made b/w 2 induviduals differ in two contrasting character.
Test cross:
Cross made b/w F1 hybrid with its recessive parent.
Back cross:
If a cross is made b/w F1 hybrid with any one of its parents.
Linkage:
It is a presence of two or more genes on the chromosomes as a result the genes inherited together more offenly.
Euchromatin:
Light strain
Less condensed
G snd C are more rich.
Heterochromatin:
Dark strain
More condensed
A and T are more.
Crossing over:
An exchange of homologous segments b/w the non sister chromatids.
It occurs during pachytene of meosis- 1
Recombination occurs during crossing over.
Submitted by DB 60
1.Plasmid:
ReplyDeleteIn addition to the nucleoid,bacterial cytoplasm normally contains one or more circular molecules of double stranded DNA called plasmids.
2.Mesosomes:
In bacterial cells, the plasma membrane shows infoldings invading the cytoplasm. It took part in respiration in mitochondria.
3.Mitochondria :
It is a double membrane bounded cell organelle having disc shaped. The inner membrane contains several infoldings called cristae.it is the power house of the cell.
4.Suicidal bags :
During starvation the lysosomes kill themselves and release undigested food matetial .
5.Nucleosome model :
The chromosomes are in the form of chromatin material and appears like a bead like structure called nucleisome. It contains four basic histone proteins and form octamer.
6.Mitochondria called semi autonomous cell organelle because they have their own DNA and ribosomes that are able to make their own proteins.
Chloroplast called semi autonomous cell organelle because have chlorophyll photosynthetic plants make own food.
7.euchromatin:light staining part of DNA. It is generally active and loosely coiled.
Heterochromatin:darkly stained portion of chromatin.dna is densely coiled and genetically inert.
8.Nucleottide:sugars +nitrogen bases+phosphate.
Nucleoside:nitrogen bases+phosphates.
9.semi conservative replication :
This would produce two copies that each contained one of the original strands and one new strand. This would leave the two original template DNA strands together in a double helix produce copy composed of two new strands.
10.DNA:
Double stranded molecule.
Deoxyribose sugar.
Contains T as nitrogenous base.
It is the hereditory material in the nucleolous of the cells.
Rna:
Single stranded nucleic acid
Contains ribose sugar
Involved in protein synthesis
Both in nucleus and cytoplasm
11.Test cross:
Cross f1hybrid with its recessive parent.
Back cross:
Cross between f1 hybrid with any one of its parents.
12.linkage:
The tendency of genes to remain together in the same chromosome.
Crossing over:
Exchange of chromosomal segments between non sister chromatids.
13.coupling:
If two alleles such as A and B come from the same parent (AABB*aabb)then they enter into same gametes and transmit together.
Repulsion:
If two alleles come from the different parents(AAbb*aaBB)enter into different gametes at the time of gametogenesis.
14.Plant breeding:
Phenomena of development of new varieties of plants possessing desirable characters from the already existing varieties.
Objectives:
Obtain high yield variety.
Improve quality, size, shape, colour, taste.
Improve disease, drought and pest resistance.
15.emasculation:
Removal of male sex organ without any damage to female reproductive organ.
16.Acclimitisation:
The newly introduced varieties has to adopt or adjust itself to the changed climatic conditions.
17.hybridisation:
Crossing of two plants of dissimilar genotype.
Objectives:
To crate genetic variation.
Segregation and recombination produce many new gene.
18.types of chromosomal mutations:
1.deletion:remove of small part
2.inversion:reattachment of same chromosome
3.translocation:repetation of same gene sequence
4.nondisjunction:transfer of a part of chromosome to another
5.duplication:failure of chromosomes to separate during meiosis.
19.inbreed lines:
Production of offsprings from the mating of individuals that are closely related genetically.
20.Mutages:
The physical or chemical agent significantly increases the mutation.
Physical mutagens:radiation and heat
Chemical mutagens:basic analogs, alkylating agents, metals, deaminating agents, intercalating agents
21.RFLP:restriction fragment length polymorphism
ReplyDeleteObjectives:
Allow the transfer of novel genes from related wild species.
Establish genetic relationships between sexually incomparable crop plants.
22.RAPD:random amplified polymorphic dna
Objectives:
These markers are employed in the construction of genetic map.
Used to distinguish between variety based on difference in DNA sequence
23.watson and crick model:
They proposed a model for DNA structure called double helix model. On the basis of this model DNA is made up of two polynucleottide chains.
24.cell brain:
Nucleus is called cellbrain because all the functions of the cell are under the control of the nucleus inside the cell.
25 .mass selection :
Number of phenotypically superior plants from field population harvesting and bulking produce together for next year's crop and repeating process till desired characters are achieved.
Pureline selection:
Process of isolating a desirable homozygous individual from mixed population and multiplying the same without contamination to release as a new variety.
Clonal selection:
A variety is propagated vegetative from a single plant called clone or single plant obtained by asexual reproduction.
Unit -4
ReplyDeleteAcclimitization:
The newly introduced varieties has to adapt or adjust itself to the changed climatic conditions. This adjustment is called acclimitization.
Hybridization:
The mating or crossing of two plants or lines of dissimilar genotype is known as hybridization.
Objectives:
To create genetic variation
Seggregation and recombination produce many new gene combinations.
Emasculation:
Removal of male sex organs or killing that part of the flower without any disturbances to female reproductive organ is known as emasculation.
Bagging:
The flower is enclosed in suitable bag to prevent random cross pollination.
Mass selection:
Harvesting and bulking their produce together for sowing the next year crop and repeating this process till desired charaters are achieved.
Pure line seletion:
Multiplying the same without contamination to release as a new variety.
Clonal selection:
All the vegetative progenies of a single plant are called a clone.
Plant breeding:
Development of new varities of plants posses desrirable characters from already exsisting variaties.
Objectives:
To abtain high yeilding variety.
To improve the quality, size etc.
Submitted by visali
Unit -5
ReplyDeleteSpontaneous mutations:
If change occurs naturally in the DNA Structure.
Induced mutations:
Change is caused by mutagens.
Chromosomal mutations:
Deletion
Inversion
Translocation
Non disjunction
Duplication.
Mutagen:
Any agent that cause change
Types of mutagens:
Physical:
Radiation and heat
Chemical:
Ethyl methane sulfonate.
DNA markers:
It is a small segment of known DNA that is used in molecular biology to identify sequence of genome in a pool of unknown DNA.
RFLP:
Restriction fragment length polymerization.
RAPD:
Rapid amplify Polymorphic DNA.
Submitted by visali.
BOTANY PAPER-V
ReplyDeleteSEMESTER-V
TOPICS:CELL BIOLOGY,GENETIC,PLANT
BREEDING
SHORT ANSWER QUESTIONS
UNIT-1 CELL BIOLOGY
1.what is Celltheory and what are it's
objectives?
A.cell theory was proposed by
scientists MATHHIAS SCHLEIDEN and
THEODOR SCHWANN(1839).
In biology, cell theory is the
historic and scientific theory
which is accepted universally.
cell theory deals with the
properties of the cell,These are the
structural and functional units of
the organism and also regarded as
basic unit of reproduction.
OBJECTIVES:
1.All living organisms are composed
of one or more cells.
2.The cell is the basic unit of
structure and organization in
organisms.
3.The cell arise from the pre
existing cells.
2.why mitochondria and chloroplast are
called semi autonomous Cell
organelles?
A.Mitochondria and chloroplast are
called semi autonomous organelles due
to following reasons:
1.They have DNA,RNA,ribosomes and
other materials required for
synthesis of their own
essential protiens.
2.They manufacture their own
enzymes.
3.They can multiply and give rise
to New organelles of same kind.
3.which of the cell organelles are said
as suicidal bags?
A.Lysosomes are called as suicidal bags
As they contain digestive enzymes
That break down waste,forgiven
materials and cellular debris,that
Are capable of digesting fats,nucleic
acids etc.
Lysosomes digest their own
Cells by their enzymes and leads to
Death .This process is also named as
AUTOLYSIS.
4.Why Plasma Membarane is called as
Semi permeable Membarane?
A.Plasma Membarane is called semi
Permeable Membarane because it allows
Only certain molecules to pass
through like:-
Oxygen
Carbon Dioxide
Minerals and Protiens etc.
It's is highly selective in deciding
Which molecules are to be allowed to
Pass through the Membarane.
5.Define Plasmid and mesosomes?
A.Plasmid:
It's typically a small circular
DNA strand in cytoplasm of a
Bacterium or protozoan.They can
Replicate independently of the
Chromosome.
eg: prokaryotic cell.
Mesosomes:
Mesosomes is a convoluted membranous
Structure i.e these are the finger
Like projections those arise from the
Wall of the plasma Membarane.
They help in secretion processes
eg: bacterial cell.
SUBMITTED BY
A.AKSHITA (DB:53)
Unit-1:CELL BIOLOGY:
ReplyDeleteWhat is mesosomes?
.The plasma membrane shows the finger like projections/folding called "mesosomes.
.mesosomes tends to increase the plasma membrane's surface and in turn also increases their enzymatic contents.
.It helps in the respiratory process .
2.why plasma membrane is called as selectively permeable membrane?
.The plasma membrane is a thin,elastic membrane around the cell.
.The plasma membrane and other intra-cellular membrane are selective in nature.such membrane allow only selected ions and some molecules to pass through them.
.The selective permeability of plasma membrane allows the cell to maintain constant internal environment .
3.why mitochondria and chloroplast are called as semi autonomous cell organelles?
.These is due to presence of a single circular naked DNA &70s type of
ribosomes.
.These organelle is present in the mitochondria and chloroplast to the mode of synthesis of proteins indicates
towards the semiautonomus or symbiotic nature.
4.Define fluid music model?
.In 1972,"Singer & Nicolson" proposed these highly advanced theory .
.The ends of the lipid molecules shows
hydrophilic and hydroponic head & tails rrespectively termed as " fluid mosaic mmodel".
5.Define sui-cidal bags?
.Lysosomes are known as "sui-cidal bags.
.Lysosomes are single membrane move immatured/embryonic cells round shape.
.Lysosomes are primary and secondary.
.primary- filled with hydrolytic enzyme,actively involve in all functions.
.secondary-filled with undigested food material .
Submitted by:
M.jyothi
DB-17
Unit-2: GENETICS:
ReplyDelete1.Define nucleosome model?
.A bead like structure of the chromatin fibres each one composed of a octomer of histone and 146 base pair containing DNA molecules.
.The nucleosome model consists of 4 pairs of basic proteins H2A,H2B,H3B,H4.
2.Define transduction and conjugation?
.Transduction:The process by which foreign DNA is introduced into a cell by a virus or viral vector.
.Conjugation:The transfer of genetic material between bacterial cell by direct cell-to-cell contact or by a bridge like connection between two cells.
3.Define translocation?
.The transfer of part of a chromosome to a different position especially,on nonhomologous chromosome.
4.Define lysis and bacteriophage?
.Lysis:The disintegration of cell by rupture of the cell wall or membrane.
.Bacteriophage:A virus that parasitizes
a bacterium by infecting it & reproducing inside it.
5.Define semi conservative model?
.The progressive separation of the two parental strands,each strand act as a template strand for the synthesis of new complementary strand.As a result two DNA molecules are produced. Each molecule one is old and anotherstrand is new strand.
Submitted by:
M.Jyothi
DB-17
UNIT-2 GENETIC MATERIAL
ReplyDelete1.Define Watson and Crick model ?
A.watson and Crick proposed DNA double
helix Model(1953).It consists of two
Phosphate chains which act as backbones.
The nitrogen base pairs are connected by
Hydrogen bonds.Both the phosphate chains
Run opposite around the central axis.
Watson and Crick are awarded with
A nobel prize in the year (1962)for their
Discovery.
2.Differntiate between nucleoside and
nucleiostide?
A.Nucleoside:
A nucleoside consists of a
Nitrogenous base covalently attached to
A sugar but without phosphate group.
Nucleotide:
A nucleotide consists of a
nitrogenous base,sugar and one to three
Phosphate groups.
3.what is semi conservative method of
replication?
A.The progressive separation of two
parental strands,each strand act as
template strand for synthetis of new
Complementary strand .As a result two DNA
Molecules are produced.each molecule has
One old and new strands
4.Define Linkage and Crossing over?
A.Linkage:
It is the presence of two or more
Genes on the chromosome as a result the
Genes inherited together more oftenly is
Called linkage.
Crossing over:
An exchange of homologous
segments between non-sister chromatids
It occurs during pachytene sub phase of
Prophase-1 of meiosis-1.
5.Define Law of independent Assortment?
A.This law is proposed by GREGOR MENDEL.He
Stated that ehen two or more characters
Are inherited,indi indivi heriditary
factors assort independently during
Gamete production, giving different
traits an equal opportunity of occuring
Together.
Submitted by
A.Akshita (DB-53)
SEMESTER-V
ReplyDeleteBOTANY PAPER-V
TITLE :Cell biology, Genetics , Plant breeding.
Short answers:
1.CELL BIOLOGY
1)What is Cell Theory and Mention it's Objectives?
Ans)Cell theory is one of the basic principals of biology . This theory says that new cells are formed from other existing cells. This theory was given by German scientists Schleiden, Schwann and Rudolf Virchow.
Objectives:
i)Living organisms composed of one (or) more cells.
ii)Cell is the most basic unit of life.
iii)All cells arise only from preexisting cells.
iv)Activity of an organism depend on the total activity of independent cells.
2)What is plasmid? Mention it's role?
Ans)Plasmids are extra chromosomal ,naked, small, circular, double stranded DNA molecules capable of self replicating and present in bacterial cells. Plasmids can integrate themselves with the main bacterial chromosome to form episomes. They are several types of plasmids F plasmid ,R plasmid etc..
3)What are mesosomes? Mention it's role?
Ans) Mesosomes are the finger like projections originated from plasma membrane into the cytoplasm of prokaryotic cells .The mesosomes are filled with respiratory enzymes.
The main function of mesosomes to perform respiration,it also increase the surface area of cell membrane, it also performs DNA replication.
4 ) Why mitochondria and chloroplast are called semiautonomous cell organelles?
Ans)Mitochondria and Chloroplast are called semi-autonomous cell organelles because they have their own genetic material and are capable of synthesising proteins required for their functioning.It also have ability to undergo auto catalysis and heterocatalysis.
5)Why Nucleus is called cell brain?
Ans) Replication occurs in the nucleus so it is called cell brain.It also holds information needed to conduct most of the cells function.
II)GENETICS
ReplyDelete1)Semi conservative method of replication:.
Semiconservative replication produce two copies that each contained one of the original strand i.e,parental strand and one new strand i.e, daughter strand .semiconservative replication leaves the two original template DNA strands together in a double helix& produce a copy composed of two new strands containing of all the new DNA base pairs.
2)Hershey -chase experiment:
This experiment help it to confirm that DNA is a genetic material .They used T2 phage ,a bacteriophage. The phage infects a bacterium by attaching to it and injecting it's genetic material into it. They put labels on phage DNA with radioactive phosphorus.
They clearly showed that DNA of T2 phage is transmitted from one generation to next while proteins are not transmitted .Atleast in T2. phage ,DNA is genetic material.
3)Watson and Crick model:
They proposed double helix structure of DNA the also received a noble prize in 1962.
DNA is a double standard helical molecule. It consists of two sugar phosphate back bones on the outside held together by hydrogen bond between pairs of nitrogenous bases on inside.
4)Clover leaf model:
Holley proposed cloverleaf model in order to explain the structure of t-rna According to this model t-rna consists of 3 loop like structures.
The 3 loop are collected together with the help of an unequal stalk fight structure one side of a stalk is 3'end and another side is 5' end. The loop that is present opposite to a stalk called anticodon loop (or) Amino acid attachment site. In this loop only specific type of amino acid acid with specific triplet cordon attached during the process of protein synthesis. The remaining 2 lateral loops are enzyme recognising site and ribosomal recognising site .Transfer RNA identify and transport specific type of amino acid to the site of protein synthesis.
5)Nucleosome model:
The nucleosome is a bead like inside the nucleus if observed under the electron microscope.
The nucleosome consists of 8 basic proteins in the form of a core i.e, octamer.Around the core the DNA molecule wraps twice between two nucleosome a DNA is present that is called Linker DNA that is associated with a special type of protein H1 protein. Nucleosome consists the repeating uses of basic proteins and DNA in side the nucleus that is called chromatin material.
III.MENDELIAN INHERITANCE
ReplyDelete1) Testcross and Backcross?
Test cross: The cross between F1 progeny and the recessive homozygous parent is called Test cross(Tt×tt)
In test cross both the progenies are obtained in F2 generation.
Back cross: if F1 hybrid is crossed with one of its parents is called back cross.(Tt×TT/tt).When F1 hybrid is back crossed with dominant phenotype no recessive individual are obtained in the progeny.
2) Define Law of independent assortment?
Ans) It states that "two pairs of traits are combined in a hybrid segregation of one pair is independent of the other pair of characters."
3)Define Law of segregation?
Ans) It states that "two alleles of a gene when present together in a heterozygous
state do not fuse or blend in any way but remain distinct and segregate during meiosis or in the formation of gametes so that each meiotic product or gamate will carry only one of them".
4)Define linkage and crossing over?
Ans) Linkage: The tendency of genes remain together in the same chromosome is called linkage. Two (or) more genes carry on a particular chromosome are called linked genes. All the genes on a pair of homologous chromosomes collectively form linkage group.
Crossing over:The exchange of chromosomal segments between two non sister chromatids is called crossing over.The term crossing over coined by T.H Morgan in 1912.Recombinations occurs during meiosis because of crossing over .
5)Define Coupling and Repulsion theory?
Ans)Coupling theory:If two alleles such as 'AB' come from the same parent(AABB×aabb) then they will enter into the same gamates and transmit together.This is called coupling theory.
Repulsion theory: When the same alleles (A&B) come from the different parents(AAbb×aaBB) then they will enter into different gamates at the time of gametogenesis. This is called repulsion theory.
Unit-3:MENDLIAN INHERITANCE :
ReplyDelete1.Define test cross & back cross ?
.Test cross:The cross between F1 hybrid with its recessive parent .
.Back cross :If a cross is made between F1 hybrid with any one of its parent.
2.Define law of independent assortment?
. The law of independent assortment is a principle of inheritance that each heritable allele is inherited independently of one another.
3.Define law of dominance?
. The law of dominance "when two alleles of an inherited pair is heterozygous,then the allele that is expressed is dominant whereas the allele that is not expressed is recessive".
4.Define linkage and crossing over ?
.Linkage:The tendency of gene to remain together in the same chromosome .
.crossing over :An exchange of homologous segments between the non-sister chromatin .It occurs during pachytene surface of prophase-1 of meiosis-1 .Recombination of characters occur during crossing over.
5.Define coupling and repulsion theory?
. "Watson and pullet" in 1906 they discovered the phenomenon of linkage and crossing over by using "lathyrus" for their experiments .They observed coupling and repulsion process due which they proposed a theory called coupling and repulsion theory.
Coupling- If two alleles from the same parent then they enter into the same gamets and they transmit together these is called coupling.
Repulsion- when the same alleles come from the different parents then they will enter into different camera at the time of gametogenesis.
Submitted by:
M.jyothi
DB-17
IV. PLANT BREEDING
ReplyDelete1)What is Acclimatisation?
Ans)It is a phenomenon of which the individual plant species adapt to the surrounding environmental conditions .
2)What is plant breeding? Give any 2 objectives?
Ans)It is a science of changing the traits of plants in order to produce desired characteristics. It has been used to improve the quality of nutrition in products for humans and animals.
Objectives:
1) Higher yield
2) Disease and pest resistance.
3)Improved quality.
4) agronomic characters.
3)Define Mass line,Pure line, Clonal selection?
Ans) Mass line selection:
It can be defined as selection of a number of phenotypically superior seeds from the field population harvesting and bulking their produce together for sowing the next year's crop and process is repeated till desirable characters are achieved.
Pure line selection:
It can be defined as the process of isolating a desirable homozygous individuals from the mixed population and multiplying the same without contamination to release as a new variety.
Clonal selection:
A variety that is propagated vegetative from single parent is called clone. Selection of Desirable clones from the mixed population of vegetative propagated crops called clonal selection.
4)What is hybridisation?Any two objectives?
Ans) Mating (or) crossing of two plants of dissimilar genotype is called hybridisation.It does not change any genetic contents of organisms but it produces new combination of genes.
Objectives:
1)To create genetic variation,when two phenotypically different plants are brought together in F1.
2) Segregation and recombinations produce new gene combinations in F2 .
5)Define Emasculation and bagging?
Ans) Emasculation: Removal of stamens from the selected female flower is called emasculation. It is done to prevent self pollination. The emasculation can be done by many methods.
Bagging: After emasculation the female flowers are covered with the help of polythene bag . This prevents unnecessary cross pollination.
Unit -4 PLANT BREEDING :
ReplyDelete1.Define plant breeding and mention two objectives?
.The phenomenon of development of new varieties of plants possessing desirable characters from the already existing varieties .
Objectives:
1.To obtain high yielding variety .
2.To improve disease,drought resistance.
2.Define acclimitization?
.Adjustment of introduced plants in new locality a changed climatic condition.such plants are disease resistance due to change in environment but chances to adultrent seeds.
Eg:Parthenon Hysterophorous
Argentina Mexicana
3.Define hybridization ?
.The mating or crossing of two plants or lines of dissimilar genotype is called hybridization .
Objectives:
1.To create genetic variation.
2.segregation and recombination produce many new gene combination.
4.Define pure line selection ?
.It can be defined as the process of isolating a desirable homozygous individual from the mixed population and multiplying the same without contamination to release as a new variety.
5.Define clonal selection ?
.A variety that is propagated vegetative from a single plant is clone of a single plant obtained by sexual reproduction or all vegetative progenies of a single plant is called a clone.
Submitted by:
M.Jyothi
DB-17
DEAR JYOTHI,
DeletePLEASE CHECK YOUR ANSWER FOR CLONAL SELECTION
UNIT-3 MENDELIAN INHERITANCE
ReplyDelete1.Define Test cross and Back cross?
A.Test cross:
The cross between F1 progeny with
It's recessive parents is called test
Cross.
Back cross:
The cross between F1 progeny with
Any one of the parents is called back cross.
2.Diffentitae Complete Linkage from
incomplete linkage?
A.Complete linkage:
The genes are completely linked
Inherited in a set and no recombination
Is there.
The gene are usually located very near to
Each other
Incomplete linkage:
The genes are not completely
Linked and recombination may occur .
The genes may be a little far from each
Other.
3.Define Law of Dominance?
A.Law of Dominance is also called as law of
Segregation.This law is proposed by G.J
MENDEL.
"It states that When two alkelalof
an inherited pair is heterozygous then,
The allele that is expressed is dominant
Whereas the allele that is not expressed
Is recessive".
MAM I HAD WRONGLY POSTED 2 QUESTIONS IN 2ND UNIT . PLEASE CONSIDER THIS APOLOGY AND I WILL TAKE CARE FURTHERLY BY NOT COMMITING THIS MISTAKE AGAIN .
SUBMITTED BY
AKSHITA.A (DB-53)
DEAR AKSHITA,
DeleteRESEND YOUR ANSWERS
Unit -5 BREEDING, CROP IMPROVMENT & BIOTECHNOLOGY:
ReplyDelete1.Define mutagen ?write any two types of agents ?
.The physical or chemical agents which greatly enhance the mutation is called mutagen .
Physical mutagen- uv radiation
Chemical mutagen -N- Nitroso N-methyl urea.
2.Define somaclonal variation ?
.The genetic variations found in the invitro cultured cells are collectively referred as somaclonal variation .
3.Define chromosomal theory?
.These theory was proposed by Morgan. According to him genes are present in the pairs of chromosomes and the chromosomal substances binds these linked genes together during the process of inheritance.The degree of linkage is determined by distance of the gene,if the genes are closer the linkage is very strong.
4.Expand RFLP and mention objectives?
.RFLP-Restriction frangemt length polymorphism.
Objectives:
1.It is extensively used in genome analysis.
2.The variation is the restriction DNA fragment lengths between individuals of a species.
5.Define inbreeding?
. The Mating of individuals or organisms that are closely related through common ancestry .
Submitted by:
M.Jyothi
DB-17
DEAR JYOTHI,
DeleteGOOD, I WILL AWARD FULL MARKS.
STUDY WELL.
V. BREEDING,CROP IMPROVEMENT
ReplyDeleteBIOTECHNOLOGY
1)What is chromosomal mutations?Types of chromosomal mutations?
Ans) A chromosmal mutation is any change or error that occurs within the chromosome.this occurs during cell processes like mitosis and and meiosis
Types:
1)Deletion:Removal of small part.
2)Inversion: Reattachment of same chromosome.
3)Duplication: Repitition of same general sequence.
4)Translation:Transfer of a part to another part of chromosome
5)Non disjunction:Failure of chromosome to separate during meiosis.
2) Define spontaneous and induced mutations?
Ans) Spontaneous mutation:If change caused by radiation in a DNA structure.
Induced mutation:Change caused by radiation (or) environmental mutagen.
3) what is mutagen? Agents of mutagens?
Ans) The agent that significantly increases the mutation is called mutagen.
Agents:
1)Physical mutagens:
A) UV radiation.
B) Electromagnetic radiation
C) Corpuscular radiation
2)Chemical mutagens:
A) Dimethyl sulphate
B) Sodium azide
C) Ethyl methane sulfonate
4)DNA markers? And role in plant breeding?
Ans) It is a fragment of DNA that is associated with in the genome in order to trace genetic alternations especially in the branch of biotechnology and molecular biology.DNA markers are used to identify particular sequence of DNA in a pool of unknown DNA.
Ex:RFLP,RAPD.
5)Expand RFLP,RAPD?
Ans)RFLP: Restriction fragments length polymorphism.
RAPD: Rapid. amplifier polymorphic DNA.
DEAR JYOTHI,
DeleteIN VTH question- no coma after rapid
DEAR MADHURI,
ReplyDeletePLEASE CHECK YOUR FOR SPONTANEOUS AND INDUCED MUTATIONS.
WRONG ANSWER.
1)Spontaneous mutation: If changes occurs naturally in a DNA structure is called spontaneous mutation
Delete2)Induced mutation:changes caused by radiation (or) environment(or) mutagen.
UNIT-4 PLANT BREEDING
ReplyDelete1.What is Plant Breeding and list few
objectives?
A. Plant breeding is the process by which
humans change the characteristics of
plants over time to make them better
crops and more nourishing food. In its
mostsimple form, breeding consists of
selecting the best plants in a given
field, growing them to full seed and then
using that seed to grow further
generations.
Objectives:
The main objectives are
i.High Yielding
ii.Disease Resistance
2. Define Acclimatization.
A. Acclimatization is the phenomenom of an
intoduced plant to adapt or adjust to the
new environmental conditions.
3. Define Introduction and give any two
merits?
A. Introduction is the earliest of the
methods followed in plant breeding.
Established plants of one area are taken
to the newer area for the use of
mankind.
Merits:
i.It is a very quick and economical method of crop improvement.
ii.It may provide an entirely a new crop species. Maize,Potato,tomato are the best examples for introduction.
4. Define Mass, Pureline and Clonal
Selection?
A. Mass Selection:
Selection of a number of
phenotypically superior plant seeds from
the field population,Mass selection is
based on phenotype (external
characters).It cannot bring any new
change in the genotype. It can be
practiced in both self-pollinated and
cross-pollinated crops.
Pureline Selection:
The process of isolating a desirable
homozygous individual from the mixed
population and selfing the same without
contamination to release as a new
variety.It is commonly used to improve
the self- pollinated crops.
Clonal Selection:
A variety that is propagated
vegetative from a single plant is called
clone.Selection of desirable clones from
the mixed population of vegetative
propagated crops is known as clonal
selection.
5.Define emasculation, bagging and tagging.
A. Emasculation:
The removal of anthers from
selected plant without disturbing
The female reproductive organs this
Process is called emasculation.
Bagging:
The process of covering the selected
female flower with the polythene cover or
butter paper.This process prevents cross
Pollination.
Tagging:
This process takes place in
hybridization,the plant or inflorescence
That is selected is provided with a tag
Made of copper and written with zinc
pencil. This gives the information about
*Place of collection
* Names of selected parents
* Time of maturation etc
SUBMITTED BY
AKSHITA.A (DB-53)
UNIT-5 CROP IMPROVEMENT AND
ReplyDeleteBIOTECHNOLOGY
1. Expand RFLP and mention it's objectives.
A. RFLP- Restriction Fragment Length
Polymerization.
Objectives:
*Allow the transfer of novel genes
from related wild species.
* Establish genetic relationships
between sexually incompatible crop
plants.
2. Define RAPD and mention it's objectives.
A. RAPD-
Random Amplified Polymorphic DNA
Objectives:
*RAPD markers are employed in the
construction of genetic maps.
*RAPD is used to distinguish between
variety is based on difference in DNA
sequence.
3. Define Somaclonal Variations.
A. Somaclonal variation is the variation
seen in plants that have been produced
by plant tissue culture. Chromosomal
rearrangements are an important source
of this variation.
Objectives:
*Somaclonal variation leads to the
creation of additional genetic
variability.
*The major likely benefit of
somaclonal variation is plant/crop
improvement.
4. Define Molecular Breeding.
A. Molecular breeding is defined as a
branch of plant breeding which utilizes
molecular genetic tools and approaches
for genetic improvement of crop plants.
5. What are mutagens?
A. Agents with cause mutation in the
organism are called mutagens. There are
different classes of mutagens based on
their chemical or physical properties.
All these mutagens induce mutations in
the genome by the structuralor chemical
modification of the genetic material DNA.
SUBMITTED BY
AKSHITA.A (DB-53)
Semester-5
ReplyDeletePaper-5(botany)
Assignment on cell biology,gentics and plant breeding (SAq's)
Submitted to: Dr.siva kumari
Submitted by: Balaratthnayogi (dz-58)
1) Plasmid:
A plasmid is a small DNA molecule within a cell that is physically separated from a chromosomal DNA and can replicate independently. They are most commonly found as small circular, double-stranded DNA molecules in bacteria; however, plasmids are sometimes present in archaea and eukaryotic organisms.
2) Mesosomes:
Mesosomes or chondrioids are folded invaginations in the plasma membrane of bacteria that are produced by the chemical fixation techniques used to prepare samples for electron microscopy.
3) Suicidal bags :
These enzymes also digest any kind of worn out cell organelles or foreign materials like bacteria or viruses that enter the cell. Thus, lysosomes help in keeping the cell clean. ... The released enzymes then digest their owncell and ultimately the cell dies. Hence, lysosomes are called suicide bags of the cell.
4) Satellite chromosome: Satellites are chromosomes that contain secondary constructs that serve as identifying markers. Besides the centromere, one or more secondary constrictions can also be observed in some chromosomes at metaphase.
5) Translation:
translation is the process in which ribosomes in the cytoplasm or ER synthesize proteins after the process of transcription of DNA to RNA in thecell's nucleus. ... The polypeptide later folds into an active protein and performs its functions in the cell.
6) Law of segregation:
ReplyDeleteGenes for different traits can segregateindependently during the formation of gametes. Law of dominance. Some alleles aredominant while others are recessive; an organism with at least one dominant allele will display the effect of the dominant allele.
7) Linkage and crossing over :
tendency for two or more non-allelic genes to be inherited together, because they are located more or less closely on the same chromosome.
Crossing over is the exchange of genes between two chromosomes, resulting in non-identical chromatids that comprise the genetic material of gametes. This process occurs during Prophase I of Meiosis, just prior to chromosome alignment and splitting of the cell.
8) Clover leaf model:
A highway interchange at which two highways, one crossing over the other, have a series of entrance and exit ramps resembling the outline of a four-leaf clover and enabling vehicles to proceed in either direction on either highway. adj. Resembling or shaped like a leaf of the clover plant.
9) test cross and back cross:
Test cross and backcross are two types of crosses introduced by Gregor Mendel. In test cross, a dominant phenotype is crossed with the homologous recessive genotype in order to discriminate between homologous dominant and heterozygous genotypes. In backcross, the F1 is crossed with one of the parents or genetically identical individual to the parent. The main difference between test cross and the backcross is that test cross is used to discriminate the genotype of an individual which is phenotypically dominant whereas a backcross is used to recover an elite genotype from a parent which bears an elite genotype.
10) DNA and RNA :
The structure of DNA and RNA. DNA is a double helix, while RNA is a single helix. Both have sets of nucleotides that contain genetic information. Deoxyribonucleic acid or DNA is a molecule that contains the instructions an organism needs to develop, live and reproduce.
11) plant breeding:
Plant breeding is the science of changing the traits of plants in order to produce desired characteristics. It has been used to improve the quality of nutrition in products for humans and animals.
12) acclimatization:
is the process in which an individual organism adjusts to a change in its environment (such as a change in altitude, temperature, humidity, photoperiod, or pH), allowing it to maintain performance across a range of environmental conditions.
13) pureline :
Pure-line selection involves selecting and breeding progeny from superior organisms for a number of generations until a pure line of organisms with only the desired characteristics has been established.
14) hybridization: The act or process of mating organisms of different varieties or species to create a hybrid. (molecular biology) The process of forming a double stranded nucleic acid from joining two complementary strands of DNA (or RNA) (as in nucleic acidhybridization)
The prime aim of plant breeding is to improve the characteristics of plants that they become more useful automatically and economically. Some of the objectives may be summarized as follows.
15)Plant breeding objectives:
1. Higher Yield:
Higher yield of grain, fodder, fibre, sugar, oil etc. developing hybrid varieties of Jawar, Maize, Bajara, etc.
2. Improved Quality:
The quality characters may vary from one crop to another such as grain size, shape, colour, milling and backing quality of wheat, cooks quality in rice, malting in barley. Size shape and flavour in fruits and keeping quality of vegetables, protein contents in legumes, methionine and tryptophan contents in pulses etc.
3. Disease and Pest Resistance:
Resistant varieties offer the cheapest and most convenient method of disease and pest control. They not only helps to increase the production but also stabilize the productivity e.g. Rust resistance in wheat.
16) Emasculation:
ReplyDeleteRemoval of stamens or anthers or killing the pollen of a flower without the female reproductive organ is known as emasculation. In bisexual flowers, emasculation is essential to prevent of self-pollination. In monoeciousplants, male flowers are removed. (castor, coconut) or male inflorescence is removed (maize).
17) Mutagens :
mutagen is a physical or chemical agent that changes the genetic material, usually DNA, of an organism and thus increases the frequency of mutations above the natural background level.
Mutant and mutations: mutant is an organism or a new genetic character arising or resulting from an instance of mutation
The mutations tend to occur within the sequence of genes and can be nonsense, frameshift, or insertion mutations.
18) Somoclonal variations:
Somaclonal variation is defined as geneticvariation. observed among progeny of plants regenerated from somatic. cells cultured in vitro. Although theoretically all plants. regenerated from-somatic cells should be clones, a number.
19)RAPD and RF LP:
RAPD (pronounced as "rapid") stands for 'Random Amplification of Polymorphic DNA'. ... The scientist performing RAPD creates several arbitrary, short primers (8–12 nucleotides), then proceeds with the PCR using a large template of genomic DNA, hoping that fragments will amplify. RFLP-: Restriction fragment length polymorphisms.
20) DNA. Markers:
a molecular marker (identified as genetic marker) is a fragment of DNA that is associated with a certain location within the genome. Molecular markers are used in molecular biology and biotechnology to identify a particular sequence of DNA in a pool of unknown DNA.
21) spontaneous mutations:
Spontaneous mutations arise from a variety of sources, including errors in DNA replication, spontaneous lesions, and transposable genetic elements.
22) transcription:
Transcription is the process by which the information in a strand of DNA is copied into a new molecule of messenger RNA (mRNA). DNA safely and stably stores genetic material in the nuclei of cells as a reference, or template.
23) translation:
translation is the process in which ribosomes in the cytoplasm or ER synthesize proteins after the process of transcription of DNA to RNA in the cell's nucleus. ... In translation, messenger RNA (mRNA) is decoded in a ribosome to produce a specific amino acid chain, or polypeptide.
24) molecular breeding:
Molecular breeding is an important branch ofplant breeding which is gaining increasing significance these days. Molecular breeding is of very recent origin. ... Molecular breeding is defined as a branch of plant breeding which utilizes molecular genetic tools and approaches for genetic improvement of crop plants.
25) advantages of mutations
Advantage - Survival. Mutations have allowed humans to adapt to their environment. ... Mutations have been responsible for antibiotic resistance in bacteria, sickle cell resistance to malaria, and immunity.
• UNIT-2 GENETIC MATERIAL
ReplyDelete1.Define Watson and Crick model ?
Watson and Crick proposed DNA double
helix Model(1953).It consists of two
Phosphate chains which act as backbones.
The nitrogen base pairs are connected by
Hydrogen bonds. Both the phosphate chains
Run opposite around the central axis.
Watson and Crick are awarded with
A Nobel prize in the year (1962)for their
Discovery.
2.what is semi conservative method of
replication?
A. The progressive separation of two
parental strands, each strand act as
template strand for synthetis of new
Complementary strand .As a result two DNA
Molecules are produced.each molecule has
One old and new strands
3.Define Linkage and Crossing over?
A.Linkage:
It is the presence of two or more
Genes on the chromosome as a result the
Genes inherited together more oftenly is
Called linkage.
Crossing over:
An exchange of homologous
segments between non-sister chromatids
It occurs during pachytene sub phase of
Prophase-1 of meiosis-1.
4.Define Law of independent Assortment?
A.This law is proposed by GREGOR MENDEL .He
Stated that when two or more characters
Are inherited,individually heriditary
factors assort independently during
Gamete production, giving different
traits an equal opportunity of occuring
Together.
• 5.Differntiate between nucleoside and
nucleotide ?
A .Nucleoside:
A nucleoside consists of a
Nitrogenous base covalently attached to
A sugar but without phosphate group.
Nucleotide:
A nucleotide consists of a
nitrogenous base, sugar and one to three
Phosphate groups.
submitted by:
M.haripriya
Dz-14
DEAR HARIPRIYA,
DeleteSUBMIT ASSIGNMENT PROPERLY.
unit.5
ReplyDelete1. RFLP- OBJECTIVES:
Restriction fragment length polymorphism
objectives-allow the transfer of noval genes from related wild species
establish genetic relationship between sexually incompatible crop plants
2. RAPD-objectives : Random amplified polymorphic DNA
objectives-RAPD is used to distinguish between variety is based on difference in DNA sequence
RAPD markers are employed in the construction of genetic maps
3. somaclonal variation and its objectives: somaclonal variation is the variation seen in plants that have been produced by plant tissue culture
objectives-it leads to the creation of additional genetic variability
the major likely benefit is plant/crop improvement
4.distinguish transcription from translation: transcription is the synthesis of RNA from DNA template where the code in the DNA is converted into a complementary RNA code.
translation is the synthesis of a protein from an mRNA template where the code in the mRNA is converted into an amino acid sequence in a protein.
5. molecular breeding: molecular breeding is a branch of plant breeding which utilizes molecular genetic tools and approaches of crop plants.
Unit 4 : PLANT BREEDING.
ReplyDelete1Q)Define Linkage and crossing over ?
ANS) Linkage: The tendency of a gene to remain together in the same chromosome is called linkage.
• All genes in a chromosome are together referred as linked genes & they form a linkage group.
• The total number of linkage group in an organism is equal to its haploid number of chromosomes.
Crossing over: The exchange of genes between homologous chromosomes, resulting in a mixture of parental characteristics in offspring.
2Q)What is Acclimatization ?
ANS) Acclimatization or acclimatisation is the process in which an individual organism adjusts to a change in its environment, allowing it to maintain performance across a range of environmental conditions.
3Q)Define Hybridization ? Mention any two functions.
ANS) The process of obtaining progeny through the union between the male gamete of one strain and female gamete of other strain through crossing over or artificial mating.
Two functions:
A) Hybridization is the process of crossing two genetically different individuals to create new genotypes.
B) Hybridisation is the process of cross between two different species to get a good yield ,better disease resistance plant, new variety in less cost.
4Q)Define Mass ,pure line and clonal selection ?
ANS) Mass selection is a simplest , common and oldest method of crop improvement, in which large number of plants of similar phenotype are selected and their seeds are harvested and mixed together to constitute the new variety.
Pure line selection is a method in which new variety is developed by selection of single best plant progeny among traditional varieties or land races.
Clonal selection: plants are vegetatively propagated .This is used to used to develop superior variety from the clones of vegetatively propagated plants.
5Q)Define mutations ? name any two types of agents.
ANS) A Mutation occurs when a DNA gene is damaged or changed in such a way as to alter the genetic message carried by that gene. A Mutagen is an agent of substance that can bring about a permanent alteration to the physical composition of a DNA gene such that the genetic message is changed.
Types of agents:
1. Induction of Mutation by Ionizing Radiations
2. Non-Ionizing Radiations (Ultra – Violet Rays)
3. Heat and Temperature
Submitted by:
M.haripriya
Dz-14
SEMESTER V
ReplyDeleteBOTANY PAPER V
S.SAI HARIKA(DB47)
UNIT-1 CELL BIOLOGY
1.Define Mesosomes?
ANS:Mesosomes are finger like structures they are seen in prokaryotic cell. These are the extensions of the plasma membrane.They produce respiratary enzyme.They increase the area of the obsorption in the cell.
2.What are semi autonomous cell organalls?.Why they are called so?
ANS:Mytochondria and chloroplast are called semi autonomous cell organalls.They are double membrane bounded cell organalls contains own single circular nacked DNA and 70s ribosomes.so they can live with out depending on circular DNA.But they are not completely independent.
3.why plasma membrane is called as selectively permeable membrane?
ANS:The plasma membrane is a thin,elastic membrane around the cell.The plasma membrane and other intra-cellular membrane are selective in nature.such membrane allow only selected ions and some molecules to pass through them.The selective permeability of plasma membrane allows the cell to maintain constant internal environment.
4.SUICIDAL BAGS:
ANS:Lysosomes are called as suicidal bags. They are filled with digestive enzyme. These enzymes also digest any kind of worn out cell organelles or foreign materials bacteria or virus that enter the cell.
5.Fluid mosaic Model:
ANS:The fluid mosaic model explains various observations regarding the structure of functional cell membranes. According to this model, there is a lipid bilayer in which the protein molecules are embedded. The lipid bilayer gives fluidity and elasticity to the membrane. Small amounts of carbohydrates are also found in cell membrane. The model, which was devised by SJ Singer and GL Nicolson in 1972, describes the cell membrane as a two-dimensional liquid that restricts the lateral diffusion of membrane components.
BOTANY PAPER V
S.SAI HARIKA(DB47)
UNIT-2 GENETIC MATERIAL
1.NUCLEOSIDE:
ANS:nucleosides are glycosylamimes that can be thought of an nucleotide without a phosphate.a nucleoside consists of a purine or pyrimidine base combined with deoxyribos or ribhose and is found expetially in DNA or RNA.
NUCLEOTIDE:
Nucleotide is an organic molecule that is the building block of DNA and RNA.It is made up of a phosphate group a 5-carbon sugar and nitrogenous base.
2.Give details about watson and crick:
ANS:They proposded the double helical structure of DNA.They got noble prize in 1962.
3.Give any four differences between DNA and RNA?
ANS: DNA:
I.It is a double stranded molecule acting as univeral genetic material.
II.DNA contains deoxy ribose sugar molecule in it's structure.
III.Udergoes autocatalysis and heterocatalysis.
IV.Contains Thymine as one of the nitogen base.
RNA:
I.It is a single stranded molecule which act as a genetic material in the absence of DNA molecule.
II.RNA contains ribose sugar in it's structure.
III.Undergoes translation to synthesise protein as a result of transcription by DNA.
IV.Contains Uracil instead of Thymine as nitrogen base.
4.Semi conservative method of replication.
ANS:Semiconservative replication produce two copies that each contained one of the original strand i.e,parental strand and one new strand i.e, daughter strand.semiconservative replication leaves the two original template DNA strands together in a double helix and produce a copy composed of two new strands containing of all the new DNA base pairs.
5.Hershey -chase experiment:
ANS:This experiment help it to confirm that DNA is a genetic material .They used T2 phage,a bacteriophage. The phage infects a bacterium by attaching to it and injecting it's genetic material into it. They put labels on phage DNA with radioactive phosphorus.
They clearly showed that DNA of T2 phage is transmitted from one generation to next while proteins are not transmitted .Atleast in T2. phage ,DNA is genetic material.
BOTANY PAPER V
ReplyDeleteS.SAI HARIKA(DB47)
UNIT-3 MENDELIAN INHERITANCE:
1.TEST CROSS:
ANS:The crosing of progeny of f1 generation with the recessive parent or phase is called "TEST CROSS".
BACK CROSS:
The crossing of progeny of f1 generation with either of the parent is called "BACKCROSS".
2.Define Law of independent assortment?
ANS:It states that "two pairs of traits are combined in a hybrid segregation of one pair is independent of the other pair of characters.
3.COUPLING:
ANS:If two allels such as A and B come from the same parent (AA BBxaa bb) then they will enter into the same gamet and they transmitt together this is called Coupling.
REPULSION:
When the same allels(AB) are come from differnent parents (AA bbx aa BB) then they will enter into differnt gametes at the time of the Gamatogensis.This is called Repulsion.
4.Define Law of Segregation?
ANS:It states that two alleles of a gene when present together in a heterozygous
state do not fuse or blend in any way but remain distinct and segregate during meiosis or in the formation of gametes so that each meiotic product or gamate will carry only one of them.
5.LINKAGE:
ANS:Genetically as the failure of two genes to assort independdently it occurs when two genes are cloe to each other on thne same chromosome.
CROSSING OVER:
The exchange of chromosomal segements between two non-sister chromatids it is called Crossing over. it was first coined by T.H.MORGHAN in 1912.
BOTANY PAPER V
S.SAI HARIKA(DB47)
UNIT-4 PLANT BREEDING
1.Acclimitization:
ANS:It is a phenomenon of an introduced plant to adopt or adjust to the new environmental.
2.Define Emasculation and bagging?
EMASCULATION:
ANS:Removal of stamens from the selected female flower is called emasculation. It is done to prevent self pollination. The emasculation can be done by many methods.
BAGGING:
After emasculation the female flowers are covered with the help of polythene bag This prevents unnecessary cross pollination.
3.Define Hybridization and mention any two objectives.
ANS:Individual produced as a result of cross between two genetically different parents is known as hybrid. The natural or artificial process that results in the formation of hybrid is known as hybridization.
Objectives:
I. To artificially create a variable population for the selection of types with desired combination of characters.
II.To create high yielding, disease resistant, stress resistant, commercially successful crops.
4.What is plant breeding? Give any 2 objectives?
ANS:It is a science of changing the traits of plants in order to produce desired characteristics. It has been used to improve the quality of nutrition in products for humans and animals.
Objectives:
I) Higher yield
II) Disease and pest resistance.
III)Improved quality.
IV) agronomic characters.
5.Define Mass line,Pure line, Clonal selection?
ANS:Mass line selection:
It can be defined as selection of a number of phenotypically superior seeds from the field population harvesting and bulking their produce together for sowing the next year's crop and process is repeated till desirable characters are achieved.
Pure line selection:
It can be defined as the process of isolating a desirable homozygous individuals from the mixed population and multiplying the same without contamination to release as a new variety.
Clonal selection:
A variety that is propagated vegetative from single parent is called clone. Selection of Desirable clones from the mixed population of vegetative propagated crops called clonal selection.
BOTANY PAPER V
ReplyDeleteS.SAI HARIKA(DB47)
UNIT-5 BREEDINGG,CROP IMPROVEMENT AND BIOTECHNOLOGY
1.Define chromosomal theory?
ANS:These theory was proposed by Morgan. According to him genes are present in the pairs of chromosomes and the chromosomal substances binds these linked genes together during the process of inheritance.The degree of linkage is determined by distance of the gene,if the genes are closer the linkage is very strong.
2.Expand RFLP and mention objectives?
ANS:RFLP-Restriction frangemt length polymorphism.
Objectives:
I.It is extensively used in genome analysis.
II.The variation is the restriction DNA fragment lengths between individuals of a species.
3.Define somaclonal variation ?
ANs:The genetic variations found in the invitro cultured cells are collectively referred as somaclonal variation.
4.Define mutagen ?write any two types of agents ?
ANs:The physical or chemical agents which greatly enhance the mutation is called mutagen .
Physical mutagen- uv radiation
Chemical mutagen -N- Nitroso N-methyl urea.
5.Define RAPD And mention it's objectives?
ANS:RAPD-Random Amplified Polymorphic DNA
Ojectives:
I.RAPD Markers are employed in the construction of genetic maps.
II.RAPD is used to distinguish between variety is based on difference in DNA sequence.
UNIT 1 ::Cell biology ::1) What is a Plasmid??
ReplyDeleteAns). Plasmid is the extra chromosomal DNA present in a prokaryotic cell which can replicate independently.They are small circular double stranded DNA molecules in bacteria . 2)What are Mesosomes?
Ans).Mesosomes are the infoldings of the plasma membrane in a prokaryotic cell into the cytoplasm. 3)cell brain:A) :Replication occurs in the nucleus so it is called cell brain.It also holds information needed to conduct most of the cells function. 4)why mitochondria and chloroplasts are called semi autonomous cell organelles?? A) Mitochondria and Chloroplast are called semi-autonomous cell organelles because they have their own genetic material and are capable of synthesising proteins required for their functioning.It also have ability to undergo auto catalysis and hetero catalysis. 5)) What is Cell Theory and Mention it's Objectives?
Ans)Cell theory is one of the basic principals of biology . This theory says that new cells are formed from other existing cells. This theory was given by German scientists Schleiden, Schwann and Rudolf Virchow.
Objectives:
i)Living organisms composed of one (or) more cells.
ii)Cell is the most basic unit of life.
iii)All cells arise only from preexisting cells. Unit 2::Genetics
1)Define Watson and Crick model ?
A.watson and Crick proposed DNA doublehelix Model(1953).It consists of twoPhosphate chains which act as backbones.The nitrogen base pairs are connected by Hydrogen bonds.Both the phosphate chainsRun opposite around the central axis.
Watson and Crick are awarded with
nobel prize for their discovery.
2)differntiate between nucleoside and
nucleiostide?
A.Nucleoside:
A nucleoside consists of a
Nitrogenous base covalently attached to a sugar but without phosphate group.
Nucleotide: nucleotide consists of a
nitrogenous base,sugar and one to three Phosphate groups. 3)Hershey -chase experiment:A)They proved that DNA as genetic material they .They used T2 phage ,a bacteriophage. The phage infects a bacterium by attaching to it and injecting it's genetic material into it. They put labels on phage DNA with radioactive phosphorus.
They clearly showed that DNA of T2 phage is transmitted from one generation to next while proteins are not transmitted . 4)Nucleosome model:
The nucleosome is a bead like inside the nucleus if observed under the electron microscope.
The nucleosome consists of 8 basic proteins in the form of a core i.e, octamer.Around the core the DNA molecule wraps twice between two nucleosome a DNA is present that is called Linker DNA that is associated with a special type of protein H1 protein. Nucleosome consists the repeating uses of basic proteins and DNA in side the nucleus that is called chromatin material.
5)Clover leaf model:
Holley proposed cloverleaf model in order to explain the structure of t-rna According to this model t-rna consists of 3 loop like structures.
The 3 loop are collected together with the help of an unequal stalk fight structure one side of a stalk is 3'end and another side is 5' end. The loop that is present opposite to a stalk called anticodon loop (or) Amino acid attachment site. The remaining 2 lateral loops are enzyme recognising site and ribosomal recognising site .Transfer RNA identify and transport specific type of amino acid to the site of protein synthesis.
UNIT 3,: 1)Define Test Cross and Back Cross.
ReplyDeleteA).Test Cross:The cross made between the F1 hybrid with it's recessive parent.It is done to know the homozygosity of the F1 hybrid.
Back Cross:The cross made between the F1 hybrid with any one of the parents.It is done in order to achieve offspring with a genetic identity which is closer to that of the parent.
2)Define Linkage and Crossing Over.
A).Linkage:It is the tendency of DNA sequences that are close together on a chromosome to be inherited together during the meiosis phase of sexual reproduction.
Crossing Over:It is the process where 2 homologous chromosome sister chromatids pair up with each other and exchange different segments of genetic material to form 2 recombinant chromosome sister chromatids. 3)Define coupling and repulsion theory?
. "Watson and pullet" in 1906 they discovered the phenomenon of linkage and crossing over by using "lathyrus" for their experiments .They observed coupling and repulsion process due to which they proposed a theory called coupling and repulsion theory.
Coupling- If two alleles from the same parent then they enter into the same gamets and they transmit together these is called coupling.
Repulsion- when the same alleles come from the different parents then they will enter into different camera at the time of gametogenesis. 4)Define Law of independent assortment?
A) It states that "two pairs of traits are combined in a hybrid segregation of one pair is independent of the other pair of characters
5)Define Law of segregation?
Ans) It states that "two alleles of a gene when present together in a heterozygous state do not blend in any way but remain distinct and segregate during meiosis or in the formation of gametes so that each meiotic product or gamate will carry only one of them. UNIT 4:: Plant Breeding
1)What is plant breeding? Give any 2 objectives?
Ans)It is a science of changing the traits of plants in order to produce desired characteristics. It has been used to improve the quality of nutrition in products for humans and animals.
Objectives:
1) Higher yield
2) Disease and pest resistance.
3)Improved quality.
4) agronomic characters.
((2))Define Mass line,Pure line, Clonal selection?
Ans) Mass line selection:
It can be defined as selection of a number of phenotypically superior seeds from the field population harvesting and bulking their produce together for sowing the next year's crop and process is repeated till desirable characters are achieved.
Pure line selection:
It can be defined as the process of isolating a desirable homozygous individuals from the mixed population and multiplying the same without contamination to release as a new variety.
Clonal selection:
A variety that is propagated vegetative from single parent is called clone. Selection of Desirable clones from the mixed population of vegetative propagated crops called clonal selection.
3)What is plant breeding? Give any 2 objectives?
Ans)It is a science of changing the traits of plants in order to produce desired characteristics. It has been used to improve the quality of nutrition in products for humans and animals.
Objectives:
1) Higher yield
2) Disease and pest resistance.
4)What is Acclimatisation?
Ans)It is a phenomenon of which the individual plant species adapt to the surrounding environmental conditions .
5)Define hybridization ?
The mating or crossing of two plants or lines of dissimilar genotype is called hybridization
Objectives:
1.To create genetic variation.
2.segregation and recombination produce many new gene combination.
Unit 5:: 1)what is mutagen? Agents of mutagens?
ReplyDeleteA) The agent that significantly increases the mutation is called mutagen.
Agents:
1)Physical mutagens:
A) UV radiation.
B) Electromagnetic radiation
C) Corpuscular radiation
2)Chemical mutagens:
A) Dimethyl sulphate
B) Sodium azide
(2)DNA markers and role in plant breeding?
Ans) It is a fragment of DNA that is associated with in the genome in order to trace genetic alternations especially in the branch of biotechnology and molecular biology.DNA markers are used to identify particular sequence of DNA in a pool of unknown DNA.
Ex:RFLP,RAPD.
3)Expand RFLP,RAPD?
Ans)RFLP: Restriction fragments length polymorphism.
RAPD: Rapid amplifier polymorphic DNA. 4)what are the different types of chromosomal mutations?? A)) five types of chromosomal mutations exist. They are 1)deletion 2)inversion 3)translocation 4)non disjunction 5)duplication 5)Define spontaneous and induced mutations?
A) Spontaneous mutations is defined as change occurred naturally in DNA structure.
Induced mutation:Change caused by radiation or change caused by mutagen is known as induced mutation
Third Year
ReplyDeleteSemester - 5 .
Paper - 5.
Title : Cell Biology , Genetics And Plant Breeding.
SHORT QUESTION'S AND ANSWER'S
Unit - 1
Cell Biology
Q 1.What are the Functions Of Cell Wall ?
Ans : The Cell Wall has the following Functions :
1.It gives the cells a definite shape.
2.It gives Mechanical Support and Rigidity to the cell.
3.In root cells,it helps to Absorb water from the soil by imbibition.
4.It Protects the Protoplast from turgor pressure developed in it due to intake of more water by Osmosis.
Q 2.Write Any Four Difference's Between Prokaryotic and Eukaryotic Cells ?
Ans :
● Prokaryotic Cell :-
1. Incipient Nucleus.No Nuclear Membrane.
2.No Mitosis.
3.Golgibodies , Endoplasmic Reticulum , Lysosome Are Absent .
4.Ribosomes 70s Types.
5.Made Up of DNA.
6.Found In Cytoplasm.
● Eukaryotic Cell
1.True Nucleus,Nuclear Membrane Present.
2.Mitosis Found.
3.Golgibodies, Endoplasmic Reticulum , Lysosome Present
4.Ribosomes 80s Types.
5.Made Up Of Chromatin , Nucleoprotein.
6.Found in Nucleus.
Q 3. What are Plastids ?
And : 1.Plastids are Cytoplasmic discoid bodies concerned with photosynthesis and Storage .
2.The term Plastid is derived from greek word plastikas meaning Formed or Moulded.
3.This Term was Coined by Schimper in 1885.
4.They are Present In Plant Cells and Absent from animal cells.
5.The Plastid are Broadly Classified into two types , Namely Chromoplasts and leucoplasts.
Q 4 . what Is Cell theory and Mention it's objections ?
Ans : Cell Theory is a concept proposed by scheiden (1838) and Schwann (1839) to Explain the Nature of cells . It states that -
1.The Cells are Organisms.
2.All Plants and Animals are Composed of an Assemblage of cells.
3.The Cells arise from Pre-Existing cells.
4.The Activities of an Organism are the outcome of the Activities of its individual cells.
5.The Cells contain Nucleus which controls all Activities of that cell.
Objections to Cell Theory :
The Following are the Objections Raised against cell theory :-
1.Certain Organisms are not made of cells . Eg.Viruses.
2.Certain Organisms don't Possess Nucleus .
Eg. Bacteria,Blue - Green algae,etc.
Q 5 : What is Fluid Mosaic Model ?
Ans : 1.Fluid Mosaic Model explains the Structure of Plasma Membrane.
2.This Model Was proposed by singer and Nicolson in 1972.
3.According to this Model,the Plasma Membrane consists of lipids and proteins.
4.The lipid is in the form of fluid and the Proteins are Embedded here and there in the lipid in a Mosaic pattern.
5.Hence,the name Fluid Mosaic Model.
6.It is Most accepted Model.
Q 6 : What are mesosomes? Mention it's role?
Ans : Mesosomes are the finger like projections originated from plasma membrane into the cytoplasm of prokaryotic cells .The mesosomes are filled with respiratory enzymes.
The main function of mesosomes to perform respiration,it also increase the surface area of cell membrane, it also performs DNA replication.
Q 7 : Write any Four Difference's Of Euchromatin and HeteroChromatin ?
Ans : ● Euchromatin :
1.Less Condensed.
2.Lightly Stained .
3.Gene Expressing.
4.Most Active
● HeteroChromatin
1.More Condensed.
2.Darkly Stained.
3.Gene Poor.
4.In active
Q 8 : What is Nucleosome Model ?
Ans : 1.In Eukaryotic Nucleus the Chromosomes are made up of DNA and the basic Proteins called Histone.
2.A bead Like Structure of the chromatin fibres each one Composed of a octomer of Histone and 146basepair Containing DNA molecule.
3.The Nucleosome Consists of 4 pairs of Basic Proteins called H2A , H2B , H3 and H4,around the 8 basic Proteins (octomer).
4.The DNA that present between the two Nucleosomes that is Called Linker DNA And H1 Protein is associated with linker DNA.
Q 9 : What are Nucleotides and Nucleosides ?
Ans. ● Nucleotides are defined as phosphoric acid esters of Nucleosides.
A Nucleotide is Made up of three components , Namely a nitrogen base, a pentose sugar and a phosphoric acid.
● Nucleosides : Compounds that contain nitrogen bases linked to pentose sugars called Nucleosides.
DB : 42 M.Eswar Kumar
Unit - 2
ReplyDeleteGenetic Material
Q 1 : Write any Four Difference's Between DNA and RNA ?
Ans :
● DNA :
1. Consists of two Strands of Nucleotides.
2.Deoxyribose sugar is present .
3.Pyrimidines are Cytosine and Thymine.
4.DNA replicates.
5.DNA is the gentic material.
● RNA :
1. Consists of only one strand of Nucleotides.
2.Ribose sugar is present.
3.Pyrimidines are Cytosine and uracil.
4 .Does not replicate.
5 . RNA is not a genetic material.
Q 2 : Write Short Notes on Watson and Crick ?
Ans : ● Watson and Crick in 1953 designed the Structure of DNA.
● It is Called the Watson and Crick Model of DNA.
● They were awarded with Nobel Prize in 1962 for this Work.
● According to Watson and Crick , DNA is in the form of double Helix.
Q 3 : What is Semi Conservative Replication ?
Ans : The Progressive Separation of the two parental strands , each strand act as a template strand for the synthesis of New Complementary strand .
As a result two molecule strands are produce , one strand is old and other is New Strand.
Q 4 :Define Transformation , Transduction and Conjugation ?
Ans :
• The Genetic recombination in which naked DNA from one cell can enter and integrate in another cell is Known as Genetic Transformation.
• The Genetic recombination in bacteria in which DNA is transferred from one bacteria cell to another via the bacteriophage is known as Transduction.
● The transfer of genetic material between bacterial cell by direct cell-to-cell contact or by a bridge like connection between two cells is Called Conjugation.
Q 5 : write Hershey -chase experiment Objective ?
Ans : •This experiment help it to confirm that DNA is a genetic material .
•They used T2 phage ,a bacteriophage.
•The phage infects a bacterium by attaching to it and injecting it's genetic material into it.
•They put labels on phage DNA with radioactive phosphorus.
•They clearly showed that DNA of T2 phage is transmitted from one generation to next while proteins are not transmitted .
•Atleast in T2 phage ,hence DNA is genetic material.
M.Eswar Kumar DB 42
Unit -3
ReplyDeleteMendelian inheritance
Q 1 : Define Linkage and Crossing over ?
Ans : • The tendency of two or More genes to stay together during inheritance is known as Linkage .
• Crossing Over may be defined as "the exchange of homologous segments between non sister chromatids of homologous Chromosomes " .
Q 2 : What is Test Cross and Back Cross ?
Ans : ● Test Cross : If a Cross Made Between F1 Hybrid with its recessive Parents is Called Test Cross.
● Back Cross : If a Cross made between F1 Hybrid with anyone of its parents.
Q 3 : Define coupling and repulsion theory?
Ans : "Watson and pullet" in 1906 they discovered the phenomenon of linkage and crossing over by using "lathyrus" for their experiments .They observed coupling and repulsion process due which they proposed a theory called coupling and repulsion theory.
Coupling- If two alleles from the same parent then they enter into the same gamets and they transmit together these is called coupling.
Repulsion- when the same alleles come from the different parents then they will enter into different camera at the time of gametogenesis.
Q 4 : Define Law of independent assortment?
Ans : It states that "two pairs of traits are combined in a hybrid segregation of one pair is independent of the other pair of characters."
Q 5 : Define Law of segregation?
Ans : It states that "two alleles of a gene when present together in a heterozygous
state do not fuse or blend in any way but remain distinct and segregate during meiosis or in the formation of gametes so that each meiotic product or gamate will carry only one of them".
M.Eswar Kumar DB 42
Unit - 4
ReplyDeletePlant Breeding
Q 1 : Define Plant Breeding and Mention two Objectives ?
Ans :
The Phenomena of Development of new varities of plants possessing desirable characters from the already existing varieties Called Plant breeding.
● Objectives:
1.Higher Yield and improved quality.
2.Disease and pest resistance.
Q 2 : Define Acclimatization ?
Ans : Acclimatization or acclimatisation is the process in which an individual organism adjusts to a change in its environment, allowing it to maintain performance across a range of environmental conditions.
Example : Argemone mexicana.
Q 3 : Define Clonal Selection and Mention their merit's and demerits any teo of each ?
Ans : A Variety that is propagated vegetative from a single plant is Called clone or progeny of a single plant obtained by asexual reproduction is known as clone or all vegetative progenies of a single plant are called a clone.
A Clone may be defined as a group of individual's of like genotypic composition traceable through asexual reproduction to a single ancestral zygote.
Selection of Desirable clones from mixed Population of vegetative propagated crops is known as Clonal Selection.
● Merits :
• It is the Only method to Improve the Clonal crops.
•This Method is Helpful in conserving Hybrid vigour for several generations.
● Demerits :
• In this Method no new genetic variability can be created.
• This Method is applicable only to vegetatively propagated crops.
Q 4 : Define Pure Line Selection and Mention it's Merits and Demerits any two of each ?
Ans : It can be defined as the process of isolating a desirable homozygous individual from the mixed Population and multiplying the same without contamination to release as new Variety.
● Merits :
• This is the only method to improve the local varieties of self - Pollinated crops.
• Best genotype for yield , disease resistance , insect resistance , earliness,quality etc.can be isolated from heterogeneous or mixed Population of an old Variety.
• This Method ia easier than Hybridization (Emasculation and crossing over)
● Demerits :
• It is very lengthy and laborious process.
• This Method is applicable to self Pollinated crops.it cannot be used for development of varieties in cross - Pollinated crops.
Q 5 : Define Mass Selection and write it's Merits And Demerits any two of each ?
Ans :
● Mass Selection : it Can be defined as Selection of a Number of phenotypically superior plants heads or seeds from the field Population , Harvesting and bulking their produce together for sowing the next year's crop and repeating this process till desired characters are achieved.
Mass Selection Based on phenotype (external characters ) and the Harvested seeds are composited without progeny testing.
#Merits :
• simplest , easiest and quickest method of crop improvement .
• Pollination need Not To be controlled to provide a new Variety .
#Demerits :
•Importance is given to Phenotypic characters only.
•There is no control over pollination,which causes greater heterozygosity and as a result the desirable qualities gradually diminish.
Q 6 : What is Emasculation and Bagging ?
Ans : ● Removal of male sex organs of the flower without any damage or disturbances to female reproductive organ is Known as Emasculation.
There are various Techniques of Emasculation :
1.Hand Emasculation.
2.Suction Emasculation.
3.Hot Water Emasculation.
4.Alcohol Treatment .
● Bagging : Immediately after Emasculation , the flower or the inflorescence is enclosed in suitable bag to Prevent random cross pollination .
The bags may be made up of paper,Butter Paper,Or Parchment paper, and Tied at the base of the inflorescence with thread , Pin or wire.
As the moisture and temperature become higher within the bag so fungus may develop,which may be prevented by removing the bag after 2-3 days after pollination.
M.Eswar Kumar DB 42 ( 162442)
Continued .....
ReplyDeleteUnit - 4
Plant Breeding
Q 7 : Define Hybridization and Mention any two Objectives ?
Ans : The mating or crossing of two plants or lines of dissimilar genotype is known as Hybridization.
The Chief Objectives of Hybridization is
● To create genetic variation , when two genotypically different plants are brought together in F1.
● Segregation and recombination produce many new gene combinations in F2 and later generations,i.e.,the Segregating generations.
Unit - 5
ReplyDeleteBreeding , Crop Improvement and Biotechnology
Q 1 : Define Mutagen and Name two Types Of Agents?
Ans : The Factor or Agent or Substance i.e., Responsible for the Mutation is Called "Mutagen"
● Types With Examples :
1.Physical Mutagen (Radiation and Heat )
Examples : Uv rays , gamma rays , X- rays.
2. Chemical Mutagens (Base Analogs , Alkylating agents, Intercalating agents,M etals,Deaminating agents )
Examples : Diethyl Sulfate, Sodium Azide etc.,
Q 2 : Define Somaclonal Variations and write it's Applications ?
Ans : The Genetic Variations found in the in vitro cultured cells are collectively referred to as Somaclonal Variations.
The Term Somaclonal Variations was first used by Larkin and Scowcraft (1981).
Applications :
1.Production of agronomically useful plants.
2.Resistance to disease's.
3.Improved Seed quality and
4.Resistance to Herbicides.
Q 3 : 4.Expand RFLP and mention its objectives?
Ans : RFLP-Restriction fragment length polymorphism.
Objectives:
1.It is extensively used in genome analysis.
2.The variation is the restriction DNA fragment lengths between individuals of a species.
Q 4 : Distinguish Spontaneous Mutation from Induced Mutation ?
Ans : Spontaneous Mutation : The Mutation occurring naturally is Called Spontaneous Mutation. It is due to normal cellular operations or due to random interactions with the environment.
Induced Mutation : Artificially produced mutations are called induced mutations . they are caused by certain factors called mutagens.
Mutagens may be Physical or Chemical factors.
Eg. X-rays , Nitrous acid,etc.
Q 5 : Expand RAPD and Mention it's objectives ?
Ans : RAPD =Random Amplified polymorphic DNA .
Objectives:
•These markers are employed in the construction of genetic map.
• Used to distinguish between variety based on difference in DNA sequence.
Prepared By M.Eswar Kumar
Read No : 162442
Roll No : DB 42.
Balayogi(Dz-58)
ReplyDeleteCell biology , genetics ,plant breeding.
1) Plasmid:
A plasmid is a small DNA molecule within a cell that is physically separated from a chromosomal DNA and can replicate independently. They are most commonly found as small circular, double-stranded DNA molecules in bacteria; however, plasmids are sometimes present in archaea and eukaryotic organisms.
2) Mesosomes:
Mesosomes or chondrioids are folded invaginations in the plasma membrane of bacteria that are produced by the chemical fixation techniques used to prepare samples for electron microscopy.
3) Suicidal bags :
These enzymes also digest any kind of worn out cell organelles or foreign materials like bacteria or viruses that enter the cell. Thus, lysosomes help in keeping the cell clean. ... The released enzymes then digest their owncell and ultimately the cell dies. Hence, lysosomes are called suicide bags of the cell.
4) Satellite chromosome: Satellites are chromosomes that contain secondary constructs that serve as identifying markers. Besides the centromere, one or more secondary constrictions can also be observed in some chromosomes at metaphase.
5) Translation:
translation is the process in which ribosomes in the cytoplasm or ER synthesize proteins after the process of transcription of DNA to RNA in thecell's nucleus. ... The polypeptide later folds into an active protein and performs its functions in the cell.
6) Law of segregation:
ReplyDeleteGenes for different traits can segregateindependently during the formation of gametes. Law of dominance. Some alleles aredominant while others are recessive; an organism with at least one dominant allele will display the effect of the dominant allele.
7) Linkage and crossing over :
tendency for two or more non-allelic genes to be inherited together, because they are located more or less closely on the same chromosome.
Crossing over is the exchange of genes between two chromosomes, resulting in non-identical chromatids that comprise the genetic material of gametes. This process occurs during Prophase I of Meiosis, just prior to chromosome alignment and splitting of the cell.
8) Clover leaf model:
A highway interchange at which two highways, one crossing over the other, have a series of entrance and exit ramps resembling the outline of a four-leaf clover and enabling vehicles to proceed in either direction on either highway. adj. Resembling or shaped like a leaf of the clover plant.
9) test cross and back cross:
Test cross and backcross are two types of crosses introduced by Gregor Mendel. In test cross, a dominant phenotype is crossed with the homologous recessive genotype in order to discriminate between homologous dominant and heterozygous genotypes. In backcross, the F1 is crossed with one of the parents or genetically identical individual to the parent. The main difference between test cross and the backcross is that test cross is used to discriminate the genotype of an individual which is phenotypically dominant whereas a backcross is used to recover an elite genotype from a parent which bears an elite genotype.
10) DNA and RNA :
The structure of DNA and RNA. DNA is a double helix, while RNA is a single helix. Both have sets of nucleotides that contain genetic information. Deoxyribonucleic acid or DNA is a molecule that contains the instructions an organism needs to develop, live and reproduce.
11) plant breeding:
ReplyDeletePlant breeding is the science of changing the traits of plants in order to produce desired characteristics. It has been used to improve the quality of nutrition in products for humans and animals.
12) acclimatization:
is the process in which an individual organism adjusts to a change in its environment (such as a change in altitude, temperature, humidity, photoperiod, or pH), allowing it to maintain performance across a range of environmental conditions.
13) pureline :
Pure-line selection involves selecting and breeding progeny from superior organisms for a number of generations until a pure line of organisms with only the desired characteristics has been established.
14) hybridization: The act or process of mating organisms of different varieties or species to create a hybrid. (molecular biology) The process of forming a double stranded nucleic acid from joining two complementary strands of DNA (or RNA) (as in nucleic acidhybridization)
The prime aim of plant breeding is to improve the characteristics of plants that they become more useful automatically and economically. Some of the objectives may be summarized as follows.
15)Plant breeding objectives:
1. Higher Yield:
Higher yield of grain, fodder, fibre, sugar, oil etc. developing hybrid varieties of Jawar, Maize, Bajara, etc.
2. Improved Quality:
The quality characters may vary from one crop to another such as grain size, shape, colour, milling and backing quality of wheat, cooks quality in rice, malting in barley. Size shape and flavour in fruits and keeping quality of vegetables, protein contents in legumes, methionine and tryptophan contents in pulses etc.
3. Disease and Pest Resistance:
Resistant varieties offer the cheapest and most convenient method of disease and pest control. They not only helps to increase the production but also stabilize the productivity e.g. Rust resistance in wheat.
16) Emasculation:
Removal of stamens or anthers or killing the pollen of a flower without the female reproductive organ is known as emasculation. In bisexual flowers, emasculation is essential to prevent of self-pollination. In monoeciousplants, male flowers are removed. (castor, coconut) or male inflorescence is removed (maize).
17) Mutagens :
mutagen is a physical or chemical agent that changes the genetic material, usually DNA, of an organism and thus increases the frequency of mutations above the natural background level.
Mutant and mutations: mutant is an organism or a new genetic character arising or resulting from an instance of mutation
The mutations tend to occur within the sequence of genes and can be nonsense, frameshift, or insertion mutations.
18) Somoclonal variations:
Somaclonal variation is defined as geneticvariation. observed among progeny of plants regenerated from somatic. cells cultured in vitro. Although theoretically all plants. regenerated from-somatic cells should be clones, a number.
19)RAPD and RF LP:
RAPD (pronounced as "rapid") stands for 'Random Amplification of Polymorphic DNA'. ... The scientist performing RAPD creates several arbitrary, short primers (8–12 nucleotides), then proceeds with the PCR using a large template of genomic DNA, hoping that fragments will amplify. RFLP-: Restriction fragment length polymorphisms.
20) DNA. Markers:
a molecular marker (identified as genetic marker) is a fragment of DNA that is associated with a certain location within the genome. Molecular markers are used in molecular biology and biotechnology to identify a particular sequence of DNA in a pool of unknown DNA.
21) spontaneous mutations:
ReplyDeleteSpontaneous mutations arise from a variety of sources, including errors in DNA replication, spontaneous lesions, and transposable genetic elements.
22) transcription:
Transcription is the process by which the information in a strand of DNA is copied into a new molecule of messenger RNA (mRNA). DNA safely and stably stores genetic material in the nuclei of cells as a reference, or template.
23) translation:
translation is the process in which ribosomes in the cytoplasm or ER synthesize proteins after the process of transcription of DNA to RNA in the cell's nucleus. ... In translation, messenger RNA (mRNA) is decoded in a ribosome to produce a specific amino acid chain, or polypeptide.
24) molecular breeding:
Molecular breeding is an important branch ofplant breeding which is gaining increasing significance these days. Molecular breeding is of very recent origin. ... Molecular breeding is defined as a branch of plant breeding which utilizes molecular genetic tools and approaches for genetic improvement of crop plants.
25) advantages of mutations
Advantage - Survival. Mutations have allowed humans to adapt to their environment. ... Mutations have been responsible for antibiotic resistance in bacteria, sickle cell resistance to malaria, and immunity.
UNIT 1: CELL BIOLOGY
ReplyDelete1Q) Define cell theory and it’s objectives?
ANS) cell theory is the historic scientific theory now universally accepted, that living organisms are made up of cells.
1.All living organisms are composed of one or more cells.
2.TheThe cell is the basic unit of structure and organization in organisms.
3.Cells arise from pre-existing cells.
2Q)What are plasmids and Mesosomes ?
Mesosomes: are folded invaginations in the plasma membrane of bacteria that are produced by the chemical fixation techniques used to prepare samples for electron microscopy.
Plasmids: a genetic structure in a cell that can replicate independently of the chromosomes, typically a small circular DNA strand in the cytoplasm of a bacterium or protozoan.
3Q)What is fluid mosaic model ?
ANS) The fluid mosaic model describes the structure of the plasma membrane as a mosaic of components —including phospholipids, cholesterol, proteins, and carbohydrates—that gives the membrane a fluid character. Plasma membranes range from 5 to 10 nm in thickness.
4Q)What are the functions of cell wall ?
ANS) The cell wall is an outer protective membrane in many cells including plants, fungi, algae, and bacteria. ... The main functions of the cell wall are to provide structure, support, and protection for the cell. The cell wall in plants is composed mainly of cellulose and contains three layers in many plants.
5Q) Why Mitochondria and chloroplasts are called semi autonomous cell organelles ?
ANS) Mitochondria and chloroplasts are semi autonomous cell organelles since they possess their own DNA and ribosomes. In animal cells, mitochondria have their own DNA and ribosomes.
SHORT QUESTION & ANSWERS FOR
ReplyDeleteSEMESTER- V
PAPER TITLE : CELL BIOLOGY, GENETICS &
PLANT BREEDING
1. WHAT ARE MESOSOMES? MENTION IT'S ROLE?
Ans) Mesosomes are the infoldings of the plasma membrane in a prokaryotic cell into the cytoplasm. Their main function is respiration in prokaryotic cells.It also helps in the binary fission and due to the more surface area present near it, many metabolic processes like enzymatic reactions undergo here.
2. WHAT ARE SEMI- AUTONOMOUS CELL ORGANELLES? WHY THEY CALLED SO?
Ans).The mitochondria and chloroplast are known as the semi-autonomous cell organelles in a plant cell. It is due to their ability to undergo autocatalysis and heterocatalysis.
Autocatalysis is the ability to replicate their own genetic material and heterocatalysis is the synthesis of proteins by transcription and translation.
3.CELL THEORY & ITS OBJECTIVES.
Ans) The 3 tenets of cell theory are,
* All living organisms are composed of one or more cells.
* Cell is the basic unit of structure and organization in organism.
* Cells arise from preexisting cells.
Objectives:
* Describe the structure and functions of cell membranes, cytoplasm and the nucleus.
* Contrast the cell structures of prokaryotes and eukaryotes.
4.SUICIDAL BAGS.
Ans) Lysosomes are present in animal and are membrane-bound organelles. They have single outer membrane which consists of acid hydrolase enzyme that helps in breaking-down macromolecules and a phospholipid bilayer.
Lysosomes are the cellular organelles that contain digestive enzymes that break down waste materials, foreign materials and foreign particles that entered cell. It helps the cell to process its nutrients and is responsible for destroying the cell after it has died. It is bounded by only one single membrane. It break-down the structures within the cells. So lysosomes are called suicidal bags.
5. FOUR DIFFERENCES BETWEEN PROKARYOTES & EUKARYOTES.
Ans) Prokaryotic cell:
* Single circular naked DNA is present.
* 70s type of ribosomes are present.
* Unicellular.
* Nucleus is absent.
Eukaryotic cell:
* DNA is linear and is packed with histone proteins.
* Both 70s & 80s type of ribosomes are present.
* Multicellular.
* Membrane bounded nucleus is present.
Gayathri Devi
DZ- 38
6.WHAT IS PLASMID? MENTION IT'S ROLE IN R-DNA TECHNOLOGY.
ReplyDeleteAns). Plasmid is the extra chromosomal DNA present in a prokaryotic cell which can replicate independently.They are small circular double stranded DNA molecules in bacteria.
Plasmids play a major role in genetic recombinations in R-DNA technology which are of great use in science, agriculture,medicine and genetics.The desired genes are isolated from the organisms and by the help of vectors(plasmids) genetic recombinations are done in laboratory.
7.DEFINE NUCLEOSIDE AND NUCLEOTIDE. Ans).Nucleoside: It consists of a sugar molecule attached to a nitrogen base.
Nucleotide: It consists of a sugar molecule attached to a nitrogen base and a phosphate group.
8.GIVE ANY FOUR DIFFERENCES BETWEEN DNA & RNA.
Ans) DNA:
i.It is a double stranded molecule acting as universal genetic material.
ii.DNA contains deoxy ribose sugar molecule in it's structure.
iii.It Undergoes autocatalysis and heterocatalysis.
iv.DNA has Thymine as one of the nitrogen base.
RNA:
i.It is a single stranded molecule which act as a genetic material in the absence of DNA molecule.
ii.RNA contains ribose sugar in it's structure.
iii.It Undergoes translation to synthesise protein as a result of transcription by DNA.
iv.RNA has Uracil instead of Thymine as nitrogen base.
9.DEFINE TRANSLATION.
Ans) In molecular biology, translation is the process in which ribosomes in the cytoplasm synthesize proteins after the process of transcription of DNA to RNA in the cell's nucleus. In translation, messenger RNA (mRNA) is decoded in a ribosome to produce a specific amino acid chain, or polypeptide.
10.SEMI CONSERVATION MODEL.
Ans) The generally accepted method of DNA replication, in which the two strands of the DNA helix separate and free nucleotides pair with the exposed bases on the single chains to form two new DNA molecules, each containing one original and one newly synthesized strand of DNA.
Gayathri Devi
DZ 38
11.WHAT WERE THE TYPE'S OF RNA & THEIR FUNCTIONS.
ReplyDeleteAns) There are three types of RNA.They are,
i. m-RNA- It is called messenger-RNA. It is transcribed from the DNA and carries the information for the protein synthesis.
ii. t-RNA- It is called transfer-RNA. It has stem loop structure. It carries amino acids to the site of protein synthesis and has anti-codon site which would be complementary to the mRNA sequence.
iii. r-RNA- It is called ribosomal-RNA. It is the site for the synthesis of proteins. It will help in attachment of the mRNA with the ribosomes.
12.DEFINE LINKAGE AND CROSSING OVER.
Ans) Linkage: It is the tendency of DNA sequences that are close together on a chromosome to be inherited together during the meiosis phase of sexual reproduction.
Crossing Over: It is the process where 2 homologous chromosome sister chromatids pair up with each other and exchange different segments of genetic material to form 2 recombinant chromosome sister chromatids.
13.DEFINE LAW OF DOMINANCE.
Ans) Mendel's law states that when two alleles of an inherited pair is heterozygous, then the allele that is expressed is dominant whereas the allele that is not expressed is recessive. The expression of the dominant allele suppressing the recessive allele is termed as Law of Dominance.
14.DEFINE TEST CROSS AND BACK CROSS.
Ans) Test Cross:The cross made between the F1 hybrid with it's recessive parent is called Test cross.
Back Cross:The cross made between the F1 hybrid with any one of its parents is called Back cross.
15.DEFINE HYBRIDIZATION AND MENTION ANY TWO OBJECTIVES.
Ans) The Individual produced as a result of cross between two genetically different parents is known as hybrid. The natural or artificial process that results in the formation of hybrid is known as hybridization.
Objectives:
i. To create artificially variable population for the selection of types with desired combination of characters.
ii.To create high yielding, disease resistant, stress resistant, commercially successful crops.
Gayathri Devi
DZ-38
16.DEFINE ACCLIMATIZATION.
ReplyDeleteAns) Acclimatization is the phenomenon of an introduced plant to adapt or adjust to the new environmental conditions.
17.WHAT WERE THE DIFFERENT TYPES OF CHROMOSOMAL MUTATIONS.
Ans) Types of chromosomal mutations:
* Deletion.
* Insertion.
* Inversion.
* Translocation.
18.WHAT IS PLANT BREEDING? GIVE ANY TWO OBJECTIVES.
Ans) Plant breeding is the process by which humans change the characteristics of plants over time to make them better crops and more nourishing food. In its most simple form, breeding consists of selecting the best plants in a given field, growing them to full seed and then using that seed to grow further generations.
Objectives:
i.High Yielding
ii.Disease Resistance
19.DEFINE MASS, PURELINE AND CLONAL SELECTION.
Ans) Mass Selection: Selection of a number of phenotypically superior plants heads or seeds from the field population, harvesting and bulking their produce together for sowing the next year’s crop and repeating this process till desired characters are achieved.Mass selection is based on external characters (phenotype).
Pureline Selection: The process of isolating a desirable homozygous individual from the mixed population and selfing the same without contamination to release as a new variety.It is commonly used to improve the self- pollinated crops.
Clonal Selection:A variety that is propagated vegetative from a single plant is called clone.Selection of desirable clones from the mixed population of vegetative propagated crops is known as clonal selection.
20.DEFINE EMASCULATION & BAGGING.
Ans) Emasculation: The removal or inactivation of male reproductive organs from the selected female parent without disturbing the female reproductive organ.
Bagging: The process of covering the selected female flower after artificially pollinating it with the desired pollens.
Gayathri Devi
DZ-38
21.WHAT ARE MUTAGENS?
ReplyDeleteAns) Agents with cause mutation in the organism are called mutagens. There are different classes of mutagens based on their chemical or physical properties. All these mutagens induce mutations in the genome by the structural or chemical modification of the genetic material (DNA).
22.EXPAND "RFLP" AND MENTION IT'S OBJECTIVES.
Ans) RFLP- Restriction Fragment Length Polymorphism.
Objectives:
i.Allow the transfer of novel genes from related wild species.
ii.Establish genetic relationships between sexually incompatible crop plants.
23.DEFINE "RAPD" AND MENTION IT'S OBJECTIVES.
Ans) RAPD- Random Amplified Polymorphic DNA
Objectives:
i.RAPD markers are employed in the construction of genetic maps.
ii.RAPD is used to distinguish between variety is based on difference in DNA sequence.
24.DEFINE MOLECULAR BREEDING.
Ans) Molecular breeding is defined as a branch of plant breeding which utilizes molecular genetic tools and approaches for genetic improvement of crop plants. In other words, genetic improvement of crop plants for various economic traits using molecular marker and transformation technologies is referred to as molecular plant breeding.
25.DNA MARKER.
Ans) In genetics, a DNA marker is a fragment of DNA that is associated with a certain location within the gene/ genome in order to trace genetic alterations especially in the branch of biotechnology and in molecular biology the DNA markers are used to identify particular sequence of DNA in a pool of unknown DNA.
Gayathri Devi
DZ-38
SEMESTER 5
ReplyDeleteBOTANY PAPER- V
SHORT ANSWERS.
UNIT-1
CELL BIOLOGY
1.What are the differences between Prokaryotic Cell and Eukaryotic Cell?
Ans: PROKARYOTIC CELL:
Nucleus is undefined and the nuclear material is present all over the cell.Single circular chromosome present.Plasmid is present which contains extra chromosomal genes which is used in R-DNA technology.Membrane bound organelles are absent.Genetic material lacks histone protein.
EUKARYOTIC CELL:
Nucleus is well defined and the nuclear material is bound by a nuclear membrane.Chromosomal number varies and they are of linear type.Plasmid is absent.Membrane bound organelles like mitochondria, chloroplast and etc are present.
Genetic material is associated with histone proteins.
2.What are Mesosomes.Mention it's role?
Ans: Mesosomes are the infoldings of the plasma membrane in a prokaryotic cell into the cytoplasm.
Mesosomes main function is respiration in prokaryotic cells.It also helps in the binary fisson and due to the more surface area present near it, many metabolic processes like enzymatic reactions undergo here.
3. what is Nucleosome model ?
The chromosomes are in the form of chromatin material and appears like a bead like structure called nucleisome. It contains four basic histone proteins and form octamer.
4.what are Suicidal bags of cell ?
Ans:During starvation the lysosomes kill themselves and release undigested food matetial .
5.what is cell brain ?
Ans: Nucleus is called cellbrain because all the functions of the cell are under the control of the nucleus inside the cell.
Hemanth
DB- 50
Unit - II GENETIC MATERIAL
ReplyDelete1. Give any four differences between DNA and RNA?
Ans: DNA:
It is a double stranded molecule acting as univeral genetic material.DNA contains deoxy ribose sugar molecule in it's structure.
Undergoes autocatalysis and heterocatalysis.
Contains Thymine as one of the nitogen base.
RNA:It is a single stranded molecule which act as a genetic material in the absence of DNA molecule. RNA contains ribose sugar in it's structure.Undergoes translation to synthesise protein as a result of transcription by DNA.Contains Uracil instead of Thymine as nitrogen base.
2.Define Nucleoside and Nucleotide?
Ans:
NUCLEOSIDE: It consists of a sugar molecule attached to a nitogen base.
NUCLEOTIDE:It consists of a sugar molecule attached to a nitrogen base and a phosphate group.
3.Give details about Watson and Crick?
Ans: Watson and Crick proposed the double helical structure of DNA molecule for which they received a Noble Prize in 1962 under Medicine.
4.Semi-conservative mode of DNA replication?
Ans:Semi-conservative mode of DNA replication was proposed by Watson and Crick in 1953.
They stated that each starnd in the parent DNA act as a template strand and the daughter strands are newly synthesised.The new daughter DNA contain one parental DNA strand and one newly synthesised strand.
5.Give the types of RNA and their functions?
Ans: There are three types of RNA.They are i.m-RNA-It is called messenger-RNA. It is transcribed from the DNA and carries the information for the protein synthesis.
ii.t-RNA-It is called transfer-RNA. It has stem loop structure. It carries amino acids to the site of protein synthesis and has anti-codon site which would be complementary to the mRNA sequence.
iii.r-RNA- It is called ribosomal-RNA. It is the site for the synthesis of proteins. It will help in attachment of the mRNA with the ribosomes.
HEMANTH
DB-50
Unit - III MENDILIAN INHERITANCE.
ReplyDelete1. Define law of Dominance?
Ans: Mendel's law stating that when two alleles of an inherited pair is heterozygous, then, the allele that is expressed is dominant whereas the allele that is not expressed is recessive. The expression of the dominant allele suppressing the recessive allele is termed as Law of Dominance.
2.Define Test Cross and Back Cross?
Ans: TEST CROSS:The cross made between the F1 hybrid with it's recessive parent.It is done to know the homozygosity of the F1 hybrid.
BACK CROSS:The cross made between the F1 hybrid with any one of the parents.It is done in order to achieve offspring with a genetic identity which is closer to that of the parent.
3.Define Linkage and Crossing Over?
Ans: LINKAGE:It is the tendency of DNA sequences that are close together on a chromosome to be inherited together during the meiosis phase of sexual reproduction.
CROSSING OVER:It is the process where 2 homologous chromosome sister chromatids pair up with each other and exchange different segments of genetic material to form 2 recombinant chromosome sister chromatids.
4. Define Complete Linkage and Incomplete Linkage?
Ans: COMPLETE LINKAGE: It is defined as the state in which two loci are so close together that alleles of these loci are virtually never separated by crossing over. The closer the physical location of two genes on the DNA, the less likely they are to be separated by a crossing-over event.
INCOMPLETE LINKAGE: When the genes were loosly linked on a chromosome and show higher percentage of recombination. In such condition non parental type of gametes are formed.Incomplete linkage produces new combinations of the genes in the progeny due to the formation of chiasma or crossing over in between the linked genes present on homologous chromosomes.
5. Define the second law of Mendelian Inheritance?
Ans: The second law of Mendelian Inheritance is The Law of Independant Assortment of Gametes which states that "When two or more characteristics are inherited, individual hereditary factors assort independently during gamete production, giving different traits an equal opportunity of occurring together.
Hemanth
DB-50
Unit - IV - PLANT BREEDING
ReplyDelete1.What is Plant Breeding.Give any two objectives?
Ans: Plant breeding is the process by which humans change the characteristics of plants over time to make them better crops and more nourishing food. In its most simple form, breeding consists of selecting the best plants in a given field, growing them to full seed and then using that seed to grow further generations.
Objectives:The main objectives are 1)High Yielding. 2)Disease Resistance
Plant Breeding aims to improve the characteristics of plant so that they become more desirable agronomically and economically. Thus, the chief objective of plant breeding is to develop such improved varieties of crop plants that will be commercially successful.
2.Define Acclimatization?
Ans: Acclimatization is the phenomenom of an intoduced plant to adapt or adjust to the new environmental conditions.
3.Define Introduction and give any two merits?
Ans: Introduction is the earliest of the methods followed in plant breeding. Established plants of one area are taken to the newer area for the use of mankind.
Merits: It is a very quick and economical method of crop improvement.It may provide an entirely a new crop species. Maize,Potato,tomato are the best examples for introduction.
4.Define Mass, Pureline and Clonal Selection?
Ans: Mass Selection: Selection of a number of phenotypically superior plants heads or seeds from the field population, harvesting and bulking their produce together for sowing the next year’s crop and repeating this process till desired characters are achieved.Mass selection is based on phenotype (external characters).It cannot bring any new change in the genotype. It can be practiced in both self-pollinated and cross-pollinated crops.
Pureline Selection: The process of isolating a desirable homozygous individual from the mixed population and selfing the same without contamination to release as a new variety.It is commonly used to improve the self- pollinated crops.
Clonal Selection:A variety that is propagated vegetative from a single plant is called clone.Selection of desirable clones from the mixed population of vegetative propagated crops is known as clonal selection.
5.Define emasculation and bagging?
Ans: EMASCULATION: The removal or inactivation of male reproductive organs from the selected female parent.
BAGGING: The process of covering the selected female flower after artificially pollinating it with the desired pollens.
Hemanth
DB-50
Unit - V - Breeding, Crop Improvement and Biotechnology
ReplyDelete1.Expand RFLP and mention it's objectives?
Ans: RFLP-Restriction Fragment Length Polymorphism
Objectives: Allow the transfer of novel genes from related wild species.Establish genetic relationships between sexually incompatible crop plants.
2.Define RAPD and mention it's objectives?
Ans: RAPD- Random Amplified Polymorphic DNA
Objectives: RAPD markers are employed in the construction of genetic maps.RAPD is used to distinguish between variety is based on difference in DNA sequence.
3.Define mass,pureline and clonal selection ?
Ans: Number of phenotypically superior plants from field population harvesting and bulking produce together for next year's crop and repeating process till desired characters are achieved.
PURELINE SELECTION
Process of isolating a desirable homozygous individual from mixed population and multiplying the same without contamination to release as a new variety.
CLONAL SELECTION:
A variety is propagated vegetative from a single plant called clone or single plant obtained by asexual reproduction
4.Define Molecular Breeding?
Ans: Molecular breeding is defined as a branch of plant breeding which utilizes molecular genetic tools and approaches for genetic improvement of crop plants. In other words, genetic improvement of crop plants for various economic traits using molecular marker and transformation technologies is referred to as molecular plant breeding.
5.What are mutagen?
Ans: Agents with cause mutation in the organism are called mutagens. There are different classes of mutagens based on their chemical or physical properties. All these mutagens induce mutations in the genome by the structural or chemical modification of the genetic material.
Hemanth
DB-50
UNIT 5 : Crop management and Biotechnology
ReplyDelete1Q ) Distinguish spontaneous mutations from induced mutations ?
ANS) Spontaneous mutations : A mutation that arises naturally and not as a result of exposure to mutagens.
Induced mutations : Those that result from changes caused by environmental chemicals or radiation.
2Q) Mention different types of chromosomal mutations?
ANS) Types of chromosomal mutations:
1. Deletion : piece of chromosomes is lost due to breakage.
2. Inversion : chromosome segment breaks off , segments flips arranging backwards and reattaches.
3. Translocation: occurs when gene sequence is repeated .one chromosome is transferred to other chromosome.
4. Nondisjunction : Failure of chromosome to saperate during meiosis.
3Q) Define somoclonal variations ?
ANS) Somoclonal variation : is the variation seen in plants that have been produced by plant tissue culture. Chromosomal rearrangements are an important source of this variation.
4Q) Define molecular breeding ? Mention any two objectives .
ANS) Molecular breeding is the application of molecular biology tools, often in plant breeding and animal breeding. The areas of molecular breeding include: QTL mapping or gene discovery. Marker assisted selection and genomic selection.
Objectives:
Plant breeding describes methods for the creation, selection, and fixation of superior plant phenotypes in the development of improved cultivars suited to needs of farmers and consumers. Primary goals of plant breeding with agricultural and horticultural crops have typically aimed at improved yields, nutritional qualities, and other traits of commercial value.
5Q) Expand RAPD and mention the objectives ?
ANS) Random amplified polymorphic DNA
Objectives:
•RAPD have been extensively used for number of horticultural crops in variety iden-tification, genetic purity and sex determination.
•RAPD markers are employed in the construction of genetic maps.
•RAPD markers are used for the selection of segregating populations more or less indirectly, during plant breeding.
T.sireesha (DZ-10) .
ReplyDeleteBOTANY PAPER-V
SEMESTER-V
TOPICS:CELL BIOLOGY,GENETIC,PLANT
BREEDING
1.What are Mesosomes? Ans:Mesosomes are the infoldings of the plasma membrane in a prokaryotic cell into the cytoplasm.
Mesosomes main function is respiration in prokaryotic cells.It also helps in the binary fisson and excretion of enzyme. 2.What is a plasmid ? Ans: A gentic structure in a cell that can replicate independently of the chromosome Typically small circular DNA strands in the cytoplasm of the bacterium. 3.Why mitochondria & chloroplast are called semi autonomous cell organelles? Ans: Mitochondria called semi autonomous cell organelle because they have their own DNA and ribosomes that are able to make their own proteins.
Chloroplast called semi autonomous cell organelle because of chlorophyll photosynthetic plants make their own food. 4.suicidal bags of cell. Ans;Lysosomes are called as suicidal bags. They are filled with digestive enzyme. These enzymes also digest any kind of worn out cell organelles or foreign materials bacteria or virus that enter the cell.During starvation the lysosomes kill themselves and release undigested food matetial 5.why plasma membrane is called semi permeable membrane? Ans plasma membrane is a outermost layer of the living cell.
It is a bi-lipid layer,consisting of a few protein molecule.
Plasma membrane is called as a selectively permeable membrane, because it allows only certain molecule to pass through the cell membrane. like oxygen,carbon dioxide,minerals some protiens etc
It is highly selective in deciding which molecules are to be allowed to pass through the membrane .
6.watson & Crick model of DNA
Ans:James Watson (1928 - ) and Francis Crick (1916 - 2004) realized that Deoxyribonucleic Acid (DNA) is a double-stranded, helical molecule. It consists of two sugar-phosphate backbones on the outside, held together by hydrogen bonds between pairs of nitrogenous bases on the inside. The bases are of four types (A, C, G, & T):
Watson and Crick shared the Nobel Prize in 1962for their discovery, along with Maurice Wilkins (1916) 7.Explain nucleosome model Ans; The Nucleosome Model proposed by P. Outdet. In chromosomal organization the DNA is associated with Histone proteins .Thenucleosome is the repeating unit that consists of Core particles of octamer of Histones- H2a, H2b, H3 and H4, and 140bp DNA coiled around it.
8. What is Semi conservative method of replication?.
Ans:Semiconservative replication produce two copies that each contained one of the original strand i.e,parental strand and one new strand i.e, daughter strand .semiconservative replication leaves the two original template DNA strands together in a double helix& produce a copy composed of two new strands containing of all the new DNA base pairs.
9.Differntiate between nucleoside and nucleiostide
A.Nucleoside:A nucleoside consists of a Nitrogenous base covalently attached to A sugar but without phosphate group.
B.Nucleotide:A nucleotide consists of a nitrogenous base,sugar and one to three Phosphate groups.
10. Define Translocation: Ans: Transfer of part of a chromosome to a different position especially on a nonhomologous;especially : the exchange of parts between nonhomologous chromosomes.
UNIT-3 MENDELIAN INHERITANCE
ReplyDelete1.Define Test cross and Back cross?
A.Test cross:
The cross between F1 progeny with
It's recessive parents is called test
Cross.
Back cross:
The cross between F1 progeny with
Any one of the parents is called back cross.
2.Diffentitae Complete Linkage from
incomplete linkage?
A.Complete linkage:
The genes are completely linked
Inherited in a set and no recombination
Is there.
The gene are usually located very near
to Each other.
Incomplete linkage:
The genes are not completely
Linked and recombination may occur .
The genes may be a little far from each
Other.
3.Define Law of Dominance?
A.Law of Dominance is also called as law of
Segregation.This law is proposed by G.J
MENDEL.
"It states that When two allele of
an inherited pair is heterozygous then,
The allele that is expressed is dominant
Whereas the allele that is not expressed
Is recessive".
4.Give a detail account on coupling and
repulsion theory?
A.Wats and pullet" in 1906 they discovered
the phenomenon of linkage and crossing
over by using "lathyrus" for their
experiments .They observed coupling and
repulsion process due which they proposed
a theory called coupling and repulsion
theory.
Coupling:
If two alleles from the same parent
then they enter into the same gamets and
they transmit together these is called
coupling.
Repulsion:
when the same alleles come from the
different parents then they will enter
into different chromosome atthe time of
gametogenesis.
5.Define law of independent assortment?
A." The law of independent assortment is a principle of inheritance that each heritable allele is inherited independently of one another".
Thank you mam
Submitted by
Akshita.A(Db-53)
III.MENDELIAN INHERITANCE
ReplyDelete11Differance between test cross& back cross ? Ans ;A)Test cross- If a heterozygous dominant F1 hybrid (Tt) crosses with the recessive parent, only 50% will be tall, and the rest 50% will be dwarf.
B)Back cross-In backcross, the F1 hybrid is crossed back with any of the parent, either dominant or recessive. Backcrosses increase the useful traits in a population. For example, certain crop plant hybrids are backcrossed with wild species to recover their useful traits such as disease resistance, high yield, etc.
12.Mendel's laws of independent assortment. Ans: In the 1860s, Gregor Mendel discovered many of the principles that govern heredity. One of these principles, now called Mendel's law of independent assortment, states that allele pairs separate independently during the formation of gametes. This means that traits are transmitted to offspring independently of one another.
13.Define linkage and crossing over?
Ans: Linkage-The tendency of genes remain together in the same chromosome is called linkage. Two (or) more genes carry on a particular chromosome are called linked genes. All the genes on a pair of homologous chromosomes collectively form linkage group.
Crossing over:The exchange of chromosomal segments between two non sister chromatids is called crossing over.The term crossing over coined by T.H Morgan in 1912.Recombinations occurs during meiosis because of crossing over .
14.Define law of dominance?
Ans: The law of dominance "when two alleles of an inherited pair is heterozygous,then the allele that is expressed is dominant whereas the allele that is not expressed is recessive".
15.Define coupling & repulsion Ans:Coupling refers to the case where dominant alleles are on the same homologue chromosome and both recessive alleles are on the other homologue chromosome. Thus, the parental gametes are AB and ab. Some authors call this cis. Repulsion refers to the case where each homologous chromosome has one dominant and one recessive allele from the two genes. Thus, the parental gametes are Ab and Ab. Some authors call this trans.
III.MENDELIAN INHERITANCE 11.Differance between test cross& back cross ? Ans ;A)Test cross- If a heterozygous dominant F1 hybrid (Tt) crosses with the recessive parent, only 50% will be tall, and the rest 50% will be dwarf.
ReplyDeleteB)Back cross-In backcross, the F1 hybrid is crossed back with any of the parent, either dominant or recessive. Backcrosses increase the useful traits in a population. For example, certain crop plant hybrids are backcrossed with wild species to recover their useful traits such as disease resistance, high yield, etc.
12.Mendel's laws of independent assortment. Ans: In the 1860s, Gregor Mendel discovered many of the principles that govern heredity. One of these principles, now called Mendel's law of independent assortment, states that allele pairs separate independently during the formation of gametes. This means that traits are transmitted to offspring independently of one another.
13.Define linkage and crossing over?
Ans: Linkage-The tendency of genes remain together in the same chromosome is called linkage. Two (or) more genes carry on a particular chromosome are called linked genes. All the genes on a pair of homologous chromosomes collectively form linkage group.
Crossing over:The exchange of chromosomal segments between two non sister chromatids is called crossing over.The term crossing over coined by T.H Morgan in 1912.Recombinations occurs during meiosis because of crossing over .
14.Define law of dominance?
Ans: The law of dominance "when two alleles of an inherited pair is heterozygous,then the allele that is expressed is dominant whereas the allele that is not expressed is recessive".
15.Define coupling & repulsion Ans:Coupling refers to the case where dominant alleles are on the same homologue chromosome and both recessive alleles are on the other homologue chromosome. Thus, the parental gametes are AB and ab. Some authors call this cis. Repulsion refers to the case where each homologous chromosome has one dominant and one recessive allele from the two genes. Thus, the parental gametes are Ab and Ab. Some authors call this trans.
T.SIREESHA,DZ-10
IV.PLANT BREEDING
ReplyDelete16.Define acclimatisation? Ans:Acclimatization or acclimatisation is the process in which an individual organism adjusts to a change in its environment, allowing it to maintain performance across a range of environmental conditions.
17.What is hybridisation?Any two objectives?
Ans:Mating (or) crossing of two plants of dissimilar genotype is called hybridisation.It does not change any genetic contents of organisms but it produces new combination of genes. objectives: To evolve a variety having all the desirable eharaetcrs viz.high Yielding; high resistance to disease, drought or water-logging; higher food value, better taste etc.
(2) To produce useful variations by introducing recombinations of characters.
(3) To produce and utilize hibrid vigour i.e. "the superiority of the hybrid over its parents."
18.Define pure line& clonal selection
Ans:Pure line-It can be defined as the process of isolating a desirable homozygous individual from the mixed population and multiplying the same without contamination to release as a new variety.
Clonal selection-.A variety that is propagated vegetative from a single plant is clone of a single plant obtained by sexual reproduction or all vegetative progenies of a single plant is called a clone.
19.Define Emasculation and bagging?
Ans: Emasculation: Removal of stamens from the selected female flower is called emasculation. It is done to prevent self pollination. The emasculation can be done by many methods.
Bagging: After emasculation the female flowers are covered with the help of polythene bag . This prevents unnecessary cross pollination.
20.Define Introduction and write any two objectives
Ans: Introduction is the earliest of the methods followed in plant breeding. Established plants of one area are taken to the newer area for the use of mankind.
i.It is a very quick and economical method of crop improvement.
ii.It may provide an entirely a new crop species. Maize,Potato,tomato are the best examples for introduction.
IV.Plant breeding
ReplyDelete16.Define acclimatisation? Ans:Acclimatization or acclimatisation is the process in which an individual organism adjusts to a change in its environment, allowing it to maintain performance across a range of environmental conditions.
17.What is hybridisation?Any two objectives?
Ans:Mating (or) crossing of two plants of dissimilar genotype is called hybridisation.It does not change any genetic contents of organisms but it produces new combination of genes. objectives: To evolve a variety having all the desirable eharaetcrs viz.high Yielding; high resistance to disease, drought or water-logging; higher food value, better taste etc.
(2) To produce useful variations by introducing recombinations of characters.
(3) To produce and utilize hibrid vigour i.e. "the superiority of the hybrid over its parents."
18.Define pure line& clonal selection
Ans:Pure line-It can be defined as the process of isolating a desirable homozygous individual from the mixed population and multiplying the same without contamination to release as a new variety.
Clonal selection-.A variety that is propagated vegetative from a single plant is clone of a single plant obtained by sexual reproduction or all vegetative progenies of a single plant is called a clone.
19.Define Emasculation and bagging?
Ans: Emasculation: Removal of stamens from the selected female flower is called emasculation. It is done to prevent self pollination. The emasculation can be done by many methods.
Bagging: After emasculation the female flowers are covered with the help of polythene bag . This prevents unnecessary cross pollination.
20.Define Introduction and write any two objectives
Ans: Introduction is the earliest of the methods followed in plant breeding. Established plants of one area are taken to the newer area for the use of mankind.
i.It is a very quick and economical method of crop improvement.
ii.It may provide an entirely a new crop species. Maize,Potato,tomato are the best examples for introduction.
T.Sireesha
Dz10
V.BREEDING,CROP IMPROVEMENT,BBIOTECHNOLOGY
ReplyDelete21. Expand RFLP & their objectives Ans:RLFP:restriction fragment length polymorphism
Objectives:
Allow the transfer of novel genes from related wild species.
Establish genetic relationships between sexually incomparable crop plants.
22.Expand RAPD & objectives Ans:RAPD:random amplified polymorphic dna
Objectives:
These markers are employed in the construction of genetic map.
Used to distinguish between variety based on difference in DNA sequence
23.what is chromosomal mutation & types of chromosomal mutations? Ans :chromosomal mutation is any change or error that occurs within the chromosome. Such errors can be attributed to any mistakes or problems that occur during cell processes like mitosis and meiosis.
Basically, structural chromosomal mutations are classified into four: deletion, duplication, inversion, and translocation
24.DNA markers? And its role in plant breeding?
Ans: It is a fragment of DNA that is associated with in the genome in order to trace genetic alternations especially in the branch of biotechnology and molecular biology.DNA markers are used to identify particular sequence of DNA in a pool of unknown DNA.
Ex:RFLP,RAPD.
25.Explain mutagen& types of agents Ans:In genetics, a mutagen is a physical or chemical agent that changes the genetic material, usually DNA, of an organism and thus increases the frequency of mutationsabove the natural background level
Agents:
1)Physical mutagens:
A) UV radiation.
B) Electromagnetic radiation
C) Corpuscular radiation
2)Chemical mutagens:
A) Dimethyl sulphate
B) Sodium azide
C) Ethyl methane sulfonate
T.SIREESHA
DZ-10
Unit-1:cell biology
ReplyDelete1.cell theory and its objectives?
A.It is universally accepted that all living organisms are made up of cells , that they are the basic structural unit of all organisms and that all cells come from pre existing cells.cells are also basic unit of repeoduction.robert hook began thr scientific study on cell and also called as cell biology.
Objective:
1)all living organisms are composed of one or more cells.
2)the cell is the basic unit of structure and organisation in organisms.
3)cell arise from pre existing cell.
2)Chromosomal theory and its objectives?
A)the speculation that chromosomes might be the key to understanding heredity led several scientists to examine mendel publications.walter sutton and theodor boveri are credited woth developing the chromosomal theory of inheritance which state that chromosome carry the unit of heridity.
Objectives:
During meiosis homologous chromosomes pairs migrate as discrete structuresvthat are independant of the chromosome pairs.
Each parent synthesis gametesvthat contain only half of their chromosomal complement.
The sorting of chromosomes from each homologous pair into pre-gametes appears to be random.
3)write short notes on plasmid?
A)it is a genetic structure in a cell that can replicate independantlyvof the chromosomes typically a small circular dna strand in the cytoplasm of a bacterium or protozoan.plasmid are much used in the laboratory manipulation of genes.
4)Write short notes on mesosomes?
A)these are the folded invaginations in the plasma membrane of bacteria that are produced by the chemical fixation techniques used to perpare samples for electron micromers .
5)any 4 differences between prokaryotic and eukaryotic cells?
A)nucleus is absent in prokaryotic cells where as present in eukaryotic cells.
2.the no.of chromosomes are one - but not true chromosome - plasmid type in prokaryotic cell where as in eukaryotic cell thare more than one chromosome.
3.the cell type in prokaryotic cell is usually unucellular and in eukaryotic cell usually multicellular type.
4.true menbrane bound nucleus is absent in prokaryotic cell where as it is present in eukaryotic cell.
Submitted by,
Navya.ch
Db:58
Unit-2 genetics :
ReplyDelete1)define transduction,conjugation?
A)transduction:it is a process by which foreign dna is inrtoduced into a cell by a virus or viral vector.an example is the viral transfer of dna from one bacterium to another .it does not require physical contact between the cell donating dna and cell receiving dna.
Conjugation:bacterial conjugation is thr tranfer of genetic material between bacterial cells by direct cell to cell contact or a bridge like connection between two cells.
2)watson and crick model?
A)watson and crick had explained the structure of the ds dna .in that , the dna is a doublestranded helical molecule.it consists of two sugar phosphate backbones on the outside,held together by hydrogen bonds between pairs of nitrogen bases in the inside of dna.
3)define nucleotide and nucleoside?
A)nuceloside:it consists of simply a nucleobase termed a nitrogenous base of either ribose or deoxyribose.
Nucleotide:it is composed of a nucleobase ,a five carbon sugar,and one or more phosphate gruops.
4)differences between rna and dna?
A)dna is doyble stranded where as rna is a single stranded molecule.
2.dna is meant for storage of genetic information where as rna is meant for expression of genetic information.
3.dna depends on rna for the gene expression where as rna depends on protein synthesis machinery.
4.dna has four nitrogen bases namely,adenine,guanine,cytosine and thymine where as rna also has four nitrogen bases the only difference is having instead of thymine rna comprises of uracil.
5)semi conservative model?
A)the progressive separation of 2 parental strands each strand act as a tenpkate strand for the synthesis of new complimentary strand.as a result 2 dna molecule are produced in each molecule,one strand is old and another strand is new one.
Submitted by:
Navya.ch
Db-58
Unut-3:mendalian inheritance
ReplyDelete1)define law of dominance?
A)according to mendelian law of dominance one of the factor for a pair of inherital traitsvwill be dominant and the other recessive ,unless both are recessive.it means ina a cross of parents that are pure for contrasting traits only one form of the trait will appear in the next generation.
2)define law of independant assirtment?
A)according to this law , alleles separate indeoendantly during the formation of gametes this means that the trait are transmitted to offsprings independantly of one another.mendel concluded that traits are transmitted to offspring indeoendantly.
3)define linkage and crossing over?
A)linkage:the tendency if genes of characters to be inherited together because of their location on the same chromosome is called linkage.
Crossing over:it is the exchange of segments between non-sister chromatids of homologous chromosomes.it occurs during pachytene stage f prophase-1 in meiosis.it always occurs between linked genes.
4)diffenrentiate complete linkage from incomplete linkage?
A)complete linkage:when the genes are tightly linked resulting in very low percentage of recombination.in such condition only parental or new cross over type of gametes are formed.
Incomplete linkage:it produces new combinationsvof the genes in the progeny due to the formation of chiasma or crossing over in between the linked genes present on homologous chromosomes.
5)define test cross and back cross?
A)back cross:if a cross is made between f1 hybrid with any one of its parent is called back cross.
Test cross:if a cross is made between f1 hybrid with its recessive parent is called test cross.
Submitted by:
Navya.ch
Db-58
Unit-4:plant breeding
ReplyDelete1)define plant breeding and its objectives?
A)plant breeding is the science ofchanging the traitsvof plants in order to produce desired characteristics.it has been used to improve the quality of nutrution in product for humans and animals.plant breeding can be accomplished through many different techiniques rangingvfrom simply selecting plants with desirable characteristics for propogation to methods that makeup of knowledge of genetics and chromosomes to more complex.
Objectives:it is to develop such improved varieties of crop plants that will be commercially successful.
High yield of crops can be obtained.
2)define acclimatization?
A)it is process where a plant adjusts to maintain performance across a range of environmental conditions.
3)define hybridisation and objectives?
A)it is the process crossing two genetically different induviduals to result ina third individual with a different often preferable set of traits.
Objectives:to raise variations.
Recombinants and seggregated plants are obatained.
4)define mass , pure line,clonal selection?
A)mass selection:it is the simplest,commonand oldest method of crop improvement in which large no.of plants of similar phenotype are selected and their seeds are harvest and mixed together constitute the new variety.
Pure line selection:the progeny of single plant selection are kept separate not bulked together.expected result is a set of genetically homogenous lines.
Clonal sekection:progeny if a single plant obatained by asexual reproduaction is known as clone.a procedure of selecting clones from mixed population of asexuals propagating crops is referred as a clone selection.
Submitted by:
Navya.ch
Db-58
Unit-5:breeding; crop imporvement and biotechnology
ReplyDelete1)define mutational breeding and objectives?
A)the utilization of induced mutations in crop improvement is called mutational breeding.
Objectives:the variety selected should be best variety available.
The selection of a plant part varies with crop plant.
2)define mutagens and name any two types of agents?
A)mutagens:chemical molecules which include mutations are called chemicak mutagens.
Alkalyting agents:examples: sulphur method,ethyl methane sulphonate.
Acridine dyes:eg;proflavine,acridine orange,acridine yellow.
3)expand RFLP and RAPD?
A)restriction fragment length polymorphism.
RAPD:rapid amplifier polymorphic dna.
4)define spontaneous and induced mutations?
A)spontaneous : change caused by the nature is called spontaneous mutations.
Induced: the change caused bye the radiation is called induced mutation.
5)define inbreed lines?
A)the mating of individuals that are closely related or thorugh common ancestory is called as inbreeding.
Submitted by:
Navya.ch
Db-58
Q1) Define cell theory and it’s objectives?
ReplyDeleteA-cell theory is one of the basic principles of biology.
The three scientists that contributed to the development of cell
theory are German Scientists Matthias Schleiden
And Theodor Schwann and .Rudolf Virchow .
This theory states that:
(i)All living organisms are composed of cells.
(ii)Cell is the structural and functional unit of life.
(iii)cells arise from the pre-existing cells.
Objectives:
(i)Describe the structure and function of the cell membrane,
Cytoplasm and the nucleus.
(ii)contrast the cell structures of prokaryotes and eukaryotes.
Q2) Define plasmid ?
A-A-plasmid is a small circular double stranded DNA molecule
Found in bacteria that can replicate independently of the
Bacterial chromosome.
Q3)Define mesosomes?
A-Mesosome is a convoluted membranous structure formed
In a prokaryotic cell by the invagination of the plasma membrane.
It helps in the secretion processes as well as in bacterial respiration.
Q4)write 4 difference between prokaryotes and eukaryotes?
A- Prokaryotes:
(i) The prokaryotes do not have a well defined
Nucleus.
(ii) Membrane bound organelles are absent.
(iii) The prokaryotic cells are smaller than eukaryotic cell and are unicellular.
(iv)They have 70s ribosome.
B- Eukaryotes:
(i)The eukaryotes have well defined nucleus.
(ii) Membrane Bound organelles are present.
(iii)The eukaryotic cells are larger and are multicellular.
(iv)They have 80s ribosome.
Q5)Why plasma membrane is called selectively permeable membrane?
A-Plasma membrane is called selectively permeable membrane as it allows
Only certain molecules or ions to pass through it by means of active and passive
Transport.
Q6)what are the functions of cell wall?
A-(i)The cell wall provides mechanical strength and support to the cell.
(ii) The cell wall provides a barrier to protect against plant viruses and pathogens.
. (i) It gives the cell definite shape and structure.
(iii)It also helps in osmotic regulation.
(iv)It prevents the cell from rupturing due to turgor pressure.
Q7)why mitochondria and chloroplast are called semiautonomous cell organelles?
A-The mitochondria and chloroplast are called semiautonomous cell organelles because
they have their own single circular naked DNA and 70s type of ribosome..
Q8)Why lysosomes are called suicidal bags of the cell?
A-A-The secondary Lysosomes bursts during starvation and releases the undigested food in protoplasm as they kill themselves they are called suicidal bags.
Q9) Difference between Heterochromatin and Euchromatin?
A-Heterochromatin:
-(i)Heterochromatin is the darkly stained part of the chromosome.
(ii)It is more condensed.
(iii)It contain inactive genes.
(iv)Adenine and Thymine is rich in Heterochromatin.
Euchromatin:
(i)Euchromatin is the light stained part of chromosome.
(ii)It is less condensed.
(iii)It contain active genes
(iv)Guanine and cytosine are rich in Euchromatin.
Q10)Define Nucleosome Model?
A-A bead like structure of chromatin fibres each one composed of 4
Pairs of basic protein called histone i.e.H2A,H2B,H3,H4.on which DNA is
Coiled around twice. The 2 Nucleosomes are connected by the DNA called linker DNA.
This is called Nucleosome Model.
Unit-1:-CELL BIOLOGY
ReplyDelete1)Functions of cell wall:-
-it is flexible, but provides strength to cell,which helps to protect the cell against physical damage.
-it also gives the cells shape and allows the organism to maintain certain shape overall.
-it also provides protection from pathogens such as bacteria that are trying to invade the cell.
2)Mesosomes:
These are organelle of bacteria that appears as an invagination of plasma membrane and funtion either in DNA replication and cell division or excretion of enzymes.
3)Plasmids:
A genetic structure in a cell that can replicate independently of the chromosomes,typically a small circular DNA strands in the cytoplasm of the bacterium or protozoans.
4)Suisidal bags:
Lysosomes are called as Suisidal bags.They are filled with digestive enzymes.These enzymes als digest any kind of worn out cell organelles or foreign materials bacteria or viruses that enter the cell.
5)Cell theory:
All the living organisms are made up of cells.The cells are basic structural/organisational unit of all organisms and that cells come from the pre-existing cells.
Unit-2:-GENETICS
1)Nucleosome model-
A nucleosome is a basic unit of DNA packaging in eukaryotes,consisting of a segment of DNA wound in sequence around 8 histone protein cores.It is a bead like structure. This structure is often compared to thread wrapped around a pool.
2)Transduction :
It is the process by which foreign DNA is introduced into a cell by a virus or viral vector.
Example:- Viral transfer of DNA from one bacterium to another.
2)Conjugation :
The transfer of genetic material between bacterial cells by direct cell to cell contact or by a brige like connection between two cells.
3)Nucleoside:-
It consists of a sugar molecule attached to a nitrogen base.
Nucleotide:
It consists of a sugar molecule attached to a nitrogen base and a phosphate group.
4)Watson and Crick model:
They explained the structure of DNA,for which they received a Noble prize.Deoxyribonucleic acid(DNA) is a double stranded,helical molecule.It consists of two sugar-phosphate backbones on out side,held together by hydrogen bonds between pairs of nitrogenous bases inside.
5)Semi conservation model:
When the double stranded helix is replicated,each of two new double stranded DNA helices consisted of one strand from the original helix and one newly synthesized.
Unit-3:-MENDELIAN INHERITANCE
1)Test cross:
The cross between F1 hybrid with its recessive parent is called test cross.
Back cross:
If a cross is made between F1 hybrid with any one of its parent.
2)Linkage:
It is the presence of two or more genes on the chromosome as a result the genes inherited together more oftenly.
Crossing over:
An exchange of homologous segments between non-sister chromatids. It occurs during pachytene sub phase of prophase-1 of meiosis-1.Recombination of character occurs during crossing over.
3)Coupling phase:
The dominant alleles present in one chromosome and recessive alleles present in another chromosome.
Repulsion phase:
Both the dominant and recessive alleles are present in the same chromosome.
4)Law of dominance:
In a cross of parents that are pure for contrasting traits,only one form of the trait will appear in the next generation. Offspring that are hybrid for a trait will have only the dominant trait in phenotype.
5)Law of independent assortment :
It describes how different genes independently separate from one another when reproductive cells develop.It occurs during meiosis in eukaryotes. It was 1st discovered by Gregor Mendel in 1865.
Submitted by:
B.Usharani
DB-59
1.Mesosomes:
ReplyDeleteIn most of the bacterial cells, the plasma membrane shows characteristics infoldings either superficially or significantly deep,invading the cytoplasm. I took part in respiration.
2.plasmids:
In addition to the nucleoid, bacterial cytoplasm normally contains one or more circular molecules of double stranded DNA called plasmids.
3.Mitochondria:
It is a double membrane bounded cell organelle having disc shaped. The inner membrane contains several infoldings called cristae which produce stalked bodies called f1particles.
4.semi autonomous cell organelle :
Mitochondria also called semi autonomous cell organelle because they have their own DNA and ribosomes that are able to make their own proteins.
Chloroplast also called semi autonomous cell organelle because having chlorophyll and able to make food by the process of photosynthesis.
5.suicidal bags:
During starvation.,the lysosomes kill themselves and release undigested food material. Hence they called suicidal bags.
6.Hetetochromatin:
Darkly coloured portion of chromatin.
DNA is densely coiled.
Occurs near the nuclear envelop.
Euchromatin :
Light staining part of DNA.
Genetically active.
Loosely coiled DNA.
7.satellite chromosomes :
In some chromosomes one of the tip of the chromatid bear a round bulb like structure called satellite. Chromosomes containing satellites called satellite chromosomes.
8.plasma membrane called as selectively permeable membrane:
Because the membrane allows only molecules of a certain size to diffuse through it, so it is called as selectivrly permeable.
9.nucleosome model:
A nucleosome is a basic unit of DNA packing in eukaryotes consisting of a segment of DNA would in sequence around eight histone protein core.
10.prokaryotes:
No membrane bounded nucleus
Cell wall made up of peptidoglycon
No membrane bound organelles
70s type of ribosomes.
Eukaryotes :
Membrane bound nucleus
Cell wall, if present made of cellulose
Membrane bound organelles
80s type of ribosomes.
11.cell brain :
Nucleus is called cell brain because all the functions of the cell are under the control of nucleus inside the cell.
12.nucleoside:sugar +nitrogen bases
nucleotide :nucleoside +phosphate
13.semi conservative type of replication :
This would produce two copies that each contained one of the original strands and one new strand. Conservative replication would leave the two original template DNA strands together in a double helix and would produce a copy composed of two new strands containing all of the new DNA base pairs.
14.DNA:
Double stranded nucleic acid.
Deoxyribose sugar
Contains thymine as nitrogenous base
It is the genetic and hereditary materials of cells
RNA
Single stranded nucleic acid
Contains ribose sugar
Uracil used instead of thymine
Involved in protein synthesis
15.Back cross:
Cross between f1 hybrid with anyone of its parents.
Test cross:
Cross between f1 hybrid with its recessive parent.
Unit-4:-PLANT BREEDING
ReplyDelete1)Plant breeding and objectives:
It is the science of changing the traits of plants in order to produce desired characters.
-it improves yield,quality,disease resistance,drought,and frost tolerance and improve characters of crops.
- it is the science based on principles of genetics and cytogenetics.
2)Acclimatization:
It is the process in which an individual organism adjusts to a change in its environment (such as a change in altitude,temperature,humidity, photoperiod or pH) allowing it to maintain performance across a range of environmental conditions.
3)Inbreeding :
It is a technique used in selective breeding.In plant breeding, inbred lines are used as stocks for the creation of hybrid lines to make use of the effects of heterosis.Inbreeding in plants also occurs naturally in the form of self-pollination.
4)Emasculation :
Removal of stamens or anthers or killing the pollen of the flower without the female reproductive organ is known as emasculation.This process is done in plant breeding to prevent self pollination.
Bagging:
The emasculated flowers are wrapped in bags to prevent pollination by unwanted pollen grains.It is an important part of plant breeding.
5)Mass selection:
When a large number of plants of similar phenotype are selected and their seeds are mixed together to constitute a new variety is called mass selection.
Pure line selection:
Large number of plants are selected from a population of self-pollinated crop,harvested individually and their individual progenies are evaluated and the best progeny is released as a pure line vareity.So the pure line is a progeny of a single homozygous self pollinated plant.
Clonal selection:
The procedure of selection used for asexually crops is known as clonal selection, since the selected plants are used to produce new clones.
Unit-5:-BREEDING,CROP IMPROVEMENT AND BIOTECHNOLOGY
1)RFLP- Restricted Fragment Length Polymorphism.
RAPD-Rapid Amplify Polymorphic DNA.
2)Spontaneous mutation:
-It arises spontaneously from natural changes in DNA structure or from error in replication i.e., mutation results from both internal and external factors.
Induced mutations:
The changes caused by the radiations or environmental chemicals are called as induced mutations.
A number of environmental agents are capable of damaging DNA including certain chemicals and radiations.
3)Mutagen:
These are the physical or chemical agents which greatly enhance the mutations.
Physical agents-Radiations
Chemical agents-nitrogen mustard,
Hydroxylamine.
4)Molecular breeding :
The use of genetic manipulation performed at DNA molecular levels to improve characters of interest in plants and animals.
The main objective of molecular breeding is to develop plant varieties with desired traits.
5)Somaclonal variations:
It is the term used to describe the variation seen in plants that have been produced by plant tissue culture. Chromosomal rearrangments are an important source of this variation.
Somaclonal variation is not restricted to,but is particularly common in plants regenerated from callus. The variations can be genotypic or phenotypic,which in later are can be either genetic or epigenetic in origin.
Submitted by:
B.Usharani
DB-59
16.crossing over :
ReplyDeleteExchange of homologous segments between non sister chromatids
Linkage :
Two or more genes present on the same chromosome as a result the genes inherited together.
17.plant breeding :
Development of new varieties of plant possessing desirable characters from the already existing varieties.
Objectives:
To obtain high yield variety.
To improve quality, size, shape colour and taste
Improve disease drought and Ipest resistance.
18.Emasculation:
Removal of male sex organs of the selected parent without damaging to the female reproductive organ.
19.inbreeding:
Production of offsprings from the mating of individuals that are closely related.
20.Acclimitisation:
The newly introduced varieties has to adopt or adjust itself to the changed climatic conditions. This adjustment the newly introduced plant is called acclimatisation.
21.Hybridisation:
The mating or crossing of two plants of dissimilar genotype.
Objectives :
To create genetic variation
Segregation and recombination produce many new gene
22.Dna markers :
It is a small segment of known DNA that is used in molecular biology, biotechnology, to identify the sequence of genome in a pool of unknown DNA.
23.Genetics:
The study of genes, genetic variation, heredity in living organisms.
Objectives :
To learn and apply concepts of modern transmission and molecular genetics.
To identify and describe the process and purposes of cell cycle, meiosis, mitosis as well as predict the outcomes of these processes.
24.RFLP:
Restriction fragment length polymorphism
Objectives :
Allow the transfer of novel genes from related wild species.
Establish genetic relationship between sexually incompatible crop plants.
25.RAPD:
Random amplified polymorphic DNA
Objectives :
Rapd markers are employed in the construction of genetic maps
Used to distinguish between variety based on difference in. DNA sequences.
Fjjjgfgg
ReplyDeleteSK.TANVEER HUSSAIN(DB-40)
ReplyDelete1.Plasmid:
In addition to the nucleoid,bacterial cytoplasm normally contains one or more circular molecules of double stranded DNA called plasmids.
2.Mesosomes:
In bacterial cells, the plasma membrane shows infoldings invading the cytoplasm. It took part in respiration in mitochondria.
3.Mitochondria :
It is a double membrane bounded cell organelle having disc shaped. The inner membrane contains several infoldings called cristae.it is the power house of the cell.
4.Suicidal bags :
During starvation the lysosomes kill themselves and release undigested food matetial .
5.Nucleosome model :
The chromosomes are in the form of chromatin material and appears like a bead like structure called nucleisome. It contains four basic histone proteins and form octamer.
6.Mitochondria called semi autonomous cell organelle because they have their own DNA and ribosomes that are able to make their own proteins.
Chloroplast called semi autonomous cell organelle because have chlorophyll photosynthetic plants make own food.
7.euchromatin:light staining part of DNA. It is generally active and loosely coiled.
Heterochromatin:darkly stained portion of chromatin.dna is densely coiled and genetically inert.
8.Nucleottide:sugars +nitrogen bases+phosphate.
Nucleoside:nitrogen bases+phosphates.
9.semi conservative replication :
This would produce two copies that each contained one of the original strands and one new strand. This would leave the two original template DNA strands together in a double helix produce copy composed of two new strands.
10.DNA:
Double stranded molecule.
Deoxyribose sugar.
Contains T as nitrogenous base.
It is the hereditory material in the nucleolous of the cells.
Rna:
Single stranded nucleic acid
Contains ribose sugar
Involved in protein synthesis
Both in nucleus and cytoplasm
SK.TANVEER HUSSAIN,DB-40
ReplyDelete11.Test cross:
Cross f1hybrid with its recessive parent.
Back cross:
Cross between f1 hybrid with any one of its parents.
12.linkage:
The tendency of genes to remain together in the same chromosome.
Crossing over:
Exchange of chromosomal segments between non sister chromatids.
13.coupling:
If two alleles such as A and B come from the same parent (AABB*aabb)then they enter into same gametes and transmit together.
Repulsion:
If two alleles come from the different parents(AAbb*aaBB)enter into different gametes at the time of gametogenesis.
14.Plant breeding:
Phenomena of development of new varieties of plants possessing desirable characters from the already existing varieties.
Objectives:
Obtain high yield variety.
Improve quality, size, shape, colour, taste.
Improve disease, drought and pest resistance.
15.emasculation:
Removal of male sex organ without any damage to female reproductive organ.
16.Acclimitisation:
The newly introduced varieties has to adopt or adjust itself to the changed climatic conditions.
17.hybridisation:
Crossing of two plants of dissimilar genotype.
Objectives:
To crate genetic variation.
Segregation and recombination produce many new gene.
18.types of chromosomal mutations:
1.deletion:remove of small part
2.inversion:reattachment of same chromosome
3.translocation:repetation of same gene sequence
4.nondisjunction:transfer of a part of chromosome to another
5.duplication:failure of chromosomes to separate during meiosis.
19.inbreed lines:
Production of offsprings from the mating of individuals that are closely related genetically.
20.Mutages:
The physical or chemical agent significantly increases the mutation.
Physical mutagens:radiation and heat
Chemical mutagens:basic analogs, alkylating agents, metals, deaminating agents, intercalating agents
SK.TANVEER HUSSAIN,DB-40
ReplyDelete21.RFLP:restriction fragment length polymorphism
Objectives:
Allow the transfer of novel genes from related wild species.
Establish genetic relationships between sexually incomparable crop plants.
22.RAPD:random amplified polymorphic dna
Objectives:
These markers are employed in the construction of genetic map.
Used to distinguish between variety based on difference in DNA sequence
23.watson and crick model:
They proposed a model for DNA structure called double helix model. On the basis of this model DNA is made up of two polynucleottide chains.
24.cell brain:
Nucleus is called cellbrain because all the functions of the cell are under the control of the nucleus inside the cell.
25 .mass selection :
Number of phenotypically superior plants from field population harvesting and bulking produce together for next year's crop and repeating process till desired characters are achieved.
Pureline selection:
Process of isolating a desirable homozygous individual from mixed population and multiplying the same without contamination to release as a new variety.
Clonal selection:
A variety is propagated vegetative from a single plant called clone or single plant obtained by asexual reproduction.
SUBMITTED BY;
TANVEER HUSSAIN
DB-162440
GENETICS
ReplyDelete1)Test cross:
The cross is made between F1 hybrid and recessive parent is known as test cross.
Example : TT/tt
2) Back cross
The cross is made between F1 hybrid and with one of its parent is known as back cross.
(Tt x tt) or (Tt x TT)
3) Dominance :- It is the phenomenon where a character is expressed phenotypically in both homozygotes and heterozygotes
Eg: Tall - T
Recessive :- The character which is not expressed phenotypically in heterozygous conditions.
Eg: Dwarf - t
Phenotype:- The physical or external appearance of a character
Eg: Tallness / Dwarfness.
Genotype:-it is the genetic make up of an individual.
Eg:TT for tall ness
tt for dwarf ness
4) Law of dominance: - Mendel’s law of segregation states that “the two alleles of a gene when present together in a heterozygous state, do not fuse or blend in any way, but remain distinct and segregate during meiosis or in the formation of gametes so that each meiotic product or gamete will carry only one of them.
5) law of independent assortment :-
The principle originated by Gregor Mendel stating that when two or more charactertics are inherited, individual hereditary factor assort independently during gamete production giving different traits an equal opportunity of occurring together.
PLANT BREEDING
1) PLANT BREEDING: -The phenomenon of development of new varieties of plants possessing desirable characters from the already existing varieties is called plant breeding.
Objectives:-
To obtain high yielding variety.
To obtain the quantity, size, shape, colour, taste and durability of the product.
To improve disease, drought and disease resistant.
2) EMASCULATION:- in case of hybridisation programme for self-pollinated crops, it is very much essential to emasculate the plant to avoid the self-pollination. Removal
Of male sex organs or killing that part of the flower without any damage or disturbances to female reproductive organ is known as emasculation.
3) HYBRIDISATION: - the mating or crossing of two plants or lines of dissimilar genotype is known as hybridisation.
4) PURE LINE SELETION: - it can be defined as the process of isolating a desirable homozygous individual from the mixed population and multiplying the same without contamination to release as a new variety.
MASS LINE SELECTION: - It can be defined as selection of a number of phenotypically superior plants heads or seeds from the field population, harvesting and bulking their
Produce together for sowing the next year’s crop and repeating this process till desired characters are achieved.
CLONAL SELECTION:- a variety that is propagated vegetative from a single plant is called clone or progeny of a single plant obtained by asexual reproduction is known as clone or all the vegetative progenies of a single plant are called a clone.
5) ACCLIMATISATION:- Adjustment of introduced plants in a new locality band changed climatic conditions.
Eg:- Parthenium hysterophorus
Argemone maxicana
submitted by
A.Stella
dz-23
Unit-4:-PLANT BREEDING
ReplyDelete1)Plant breeding and objectives:
It is the science of changing the traits of plants in order to produce desired characters.
-it improves yield,quality,disease resistance,drought,and frost tolerance and improve characters of crops.
- it is the science based on principles of genetics and cytogenetics.
2)Acclimatization:
It is the process in which an individual organism adjusts to a change in its environment (such as a change in altitude,temperature,humidity, photoperiod or pH) allowing it to maintain performance across a range of environmental conditions.
3)Inbreeding :
It is a technique used in selective breeding.In plant breeding, inbred lines are used as stocks for the creation of hybrid lines to make use of the effects of heterosis.Inbreeding in plants also occurs naturally in the form of self-pollination.
4)Emasculation :
Removal of stamens or anthers or killing the pollen of the flower without the female reproductive organ is known as emasculation.This process is done in plant breeding to prevent self pollination.
Bagging:
The emasculated flowers are wrapped in bags to prevent pollination by unwanted pollen grains.It is an important part of plant breeding.
5)Mass selection:
When a large number of plants of similar phenotype are selected and their seeds are mixed together to constitute a new variety is called mass selection.
Pure line selection:
Large number of plants are selected from a population of self-pollinated crop,harvested individually and their individual progenies are evaluated and the best progeny is released as a pure line vareity.So the pure line is a progeny of a single homozygous self pollinated plant.
Clonal selection:
The procedure of selection used for asexually crops is known as clonal selection, since the selected plants are used to produce new clones.
Unit-5:-BREEDING,CROP IMPROVEMENT AND BIOTECHNOLOGY
1)RFLP- Restricted Fragment Length Polymorphism.
RAPD-Rapid Amplify Polymorphic DNA.
2)Spontaneous mutation:
-It arises spontaneously from natural changes in DNA structure or from error in replication i.e., mutation results from both internal and external factors.
Induced mutations:
The changes caused by the radiations or environmental chemicals are called as induced mutations.
A number of environmental agents are capable of damaging DNA including certain chemicals and radiations.
3)Mutagen:
These are the physical or chemical agents which greatly enhance the mutations.
Physical agents-Radiations
Chemical agents-nitrogen mustard,
Hydroxylamine.
4)Molecular breeding :
The use of genetic manipulation performed at DNA molecular levels to improve characters of interest in plants and animals.
The main objective of molecular breeding is to develop plant varieties with desired traits.
5)Somaclonal variations:
It is the term used to describe the variation seen in plants that have been produced by plant tissue culture. Chromosomal rearrangments are an important source of this variation.
Somaclonal variation is not restricted to,but is particularly common in plants regenerated from callus. The variations can be genotypic or phenotypic,which in later are can be either genetic or epigenetic in origin.
Submitted by:
B.Usharani
DB-59
1)Expantion 0f RFLP and its objectives?
ReplyDelete.RFLP-Restriction frangemt length polymorphism.
Objectives:
1.It is extensively used in genome analysis.
2.The variation is the restriction DNA fragment lengths between individuals of a species.
2)Inbreeding:
. The Mating of individuals or organisms that are closely related through common ancestry .
.Define mutagen ?write any two types of agents ?
.The physical or chemical agents which greatly enhance the mutation is called mutagen .
Physical mutagen- uv radiation
Chemical mutagen -N- Nitroso N-methyl urea.
3) somaclonal variation:
.The genetic variations found in the invitro cultured cells are collectively referred as somaclonal variation .
4)chromosomal theory:
These theory was proposed by Morgan. According to him genes are present in the pairs of chromosomes and the chromosomal substances binds these linked genes together during the process of inheritance.The degree of linkage is determined by distance of the gene,if the genes are closer the linkage is very strong.
CELL BIOLOGY
1)CELL THOERY
Schleiden and Schwann (1853) have proposed that cell is the basic unit of stricter and function in all life forms. This simple but basic generalisation is popularly known as cell theory.
All living organisms are made up of small microscopic fundamental and basic units called cells.
All metabolic reactions take place in cells.
Cells originate from pre existing cells.
2) MESOSOMES
Mesosomes are structures of prokaryotic cells formed by folded invaginations of the plasma membrane.
The function of mesosomes is respiration associated with the enzymes.
3) PLASMID
Plasmid is a small circular , double stranded DNA molecule in a bacteria.
It is physically separated from a chromosomal DNA and replicate independently.
Plasmids are used as vectors in molecular cloning.
4) FUNCTIONS OF CELL WALL
Cell wall is a rigid, semi permeable protective layer .
This outer cover is positioned next to the cell membrane.
It provides mechanical strength and support to cell.
It gives protection to the cell.
5)Why Nucleus is called cell brain?
Ans) Replication occurs in the nucleus so it is called cell brain.It also holds information needed to conduct most of the cells function
submitted by
A.Stella
DZ 23
Sumanjali(DB-19)
ReplyDelete1.plasmids.?
A.A genetic structure in a cell that can replicate independently of the chromosome typically small circular DNA strands in the cytoplasam of the bacterium.
2.mesosomes?
A. An organelle of bacteria that appers as an invagination of plasma membrane and function either in DNA replication and cell division or excreation of enzyme.
3.suicidal bags.?
A. Lysosomes are called as suicidal bags.they are filled with digestive enzyme.these enzymes also digest any kind of worn out cell organelles or foreign materials bacteria or virus that enter the cell.
4.Nucleosome model?
A. Anucleosome is a basic unit of DNA packing in eukaryotes,consisting of a segment of DNA wound in sequence eight histones protein cores.this structure often compared to thread wrapped around a pool.
5.cell theory
A. Living organisms are made up of cells.cells are basic structural and functional unit of all organisms.cells come from pre-existing cells.
6.Monohybrid cross?
A. The cross made between 2 individuals differ in one character.
Dihybridcross:-
The cross is made between 2 individuals differ in two contrasting character.
7.test cross:-
A. Cross made between f1 hybrid with its reccessive parents.
Back cross:-
A. If a cross us made between f1 hybrid with any one of its parents.
8.linkage..?
A. It is a presence of two or more genes on the chromosomes as a result the genes inherited together more offenly.
9.Euchromatin:-
Light strain
Less condensed
G and C are more rich
Heterochromatin:-
Dark strain
More condensed
A and T are more.
10.crossing over:-
A. An exchange of homologous segments b/w the non sister chromotids.
Its occurs during pachytene of meosis-1 recombination occurs during crossing over.
11.Emasculation:-
A. In hybridazation,removal of male sex organ without any damage to female reprodutive organ.
12.Accilimitisation:-
A. The newly introduced varieities has to adopt or adjust itself to the changed climatic conditions.
13.hybridisation..?
A. Crossing of two plants of disimilar genotype.
Objectives:-
To create genetic variation.
Segregation and recombination produce many new gene.
14.Inbreed lines:-
A. Production of offsprings from the mating of individuals that are closely related genetically.
15.plant breeding..?
A, phenomenon of development of new varieties of plants possesing desirable characters from the already existing varieties.
Objecties:-
Obtain high yield variety.
Improve quality,size,shape,colour,taste.
16.cell brain?
A. Nucleus is called cell brain because all the functions of the cell are under the control of the nucleus inside the cell.
17.Watson and crick model.
A. They proposed a model for dna structure called helix model.on the basis of this model DNA is made up of the two polynucleotides chains.
18.spontaneous mutations:-
A.if change occurs naturally in the DNA structure..
Induced mutations:-
A.change is caused by mutogens.
19.chromosomel mutations:-
A.deletion
Inversion
Translocation
Non disjuntion
Dupliation.
20.Mutogen:-
A. Any agent that cause change.
Types of mutogens:-
Physical:-radiation and heat
Chemical:-ethyl methane sulfonate.
21.DNA markers:-
A. It is a small segment of known DNA that is used in molecular biology to identify sequence of genome in a pool of unknown DNA.
22.RELP
A.restriction fragment length polymerization.
RAPD:-
Rapid amplify polymorphic DNA.
23.define translocation?
A. The transfer of part of a chromosome to a different position espercially on non homologous chromosome.
24.define lysis.and bacteriophage?
A,lysis..:-the disintegration of cell by rupture of the cell wall or membrane.
Bacteriophage:-
A virus that parasitizes a bacterium by infecting it and reproducing inside it.
25.law of independpent assortment?
A.It states that two pairs of traits are combined in a hybrid segregation of one pair is independent of the other pair of characters.
Submitted by sumanjali(DB-19)
Sumanjali(DB-19)
ReplyDelete1.plasmids.?
A.A genetic structure in a cell that can replicate independently of the chromosome typically small circular DNA strands in the cytoplasam of the bacterium.
2.mesosomes?
A. An organelle of bacteria that appers as an invagination of plasma membrane and function either in DNA replication and cell division or excreation of enzyme.
3.suicidal bags.?
A. Lysosomes are called as suicidal bags.they are filled with digestive enzyme.these enzymes also digest any kind of worn out cell organelles or foreign materials bacteria or virus that enter the cell.
4.Nucleosome model?
A. Anucleosome is a basic unit of DNA packing in eukaryotes,consisting of a segment of DNA wound in sequence eight histones protein cores.this structure often compared to thread wrapped around a pool.
5.cell theory
A. Living organisms are made up of cells.cells are basic structural and functional unit of all organisms.cells come from pre-existing cells.
6.Monohybrid cross?
A. The cross made between 2 individuals differ in one character.
Dihybridcross:-
The cross is made between 2 individuals differ in two contrasting character.
7.test cross:-
A. Cross made between f1 hybrid with its reccessive parents.
Back cross:-
A. If a cross us made between f1 hybrid with any one of its parents.
8.linkage..?
A. It is a presence of two or more genes on the chromosomes as a result the genes inherited together more offenly.
9.Euchromatin:-
Light strain
Less condensed
G and C are more rich
Heterochromatin:-
Dark strain
More condensed
A and T are more.
10.crossing over:-
A. An exchange of homologous segments b/w the non sister chromotids.
Its occurs during pachytene of meosis-1 recombination occurs during crossing over.
11.Emasculation:-
A. In hybridazation,removal of male sex organ without any damage to female reprodutive organ.
12.Accilimitisation:-
A. The newly introduced varieities has to adopt or adjust itself to the changed climatic conditions.
13.hybridisation..?
A. Crossing of two plants of disimilar genotype.
Objectives:-
To create genetic variation.
Segregation and recombination produce many new gene.
14.Inbreed lines:-
A. Production of offsprings from the mating of individuals that are closely related genetically.
15.plant breeding..?
A, phenomenon of development of new varieties of plants possesing desirable characters from the already existing varieties.
Objecties:-
Obtain high yield variety.
Improve quality,size,shape,colour,taste.
16.cell brain?
A. Nucleus is called cell brain because all the functions of the cell are under the control of the nucleus inside the cell.
17.Watson and crick model.
A. They proposed a model for dna structure called helix model.on the basis of this model DNA is made up of the two polynucleotides chains.
18.spontaneous mutations:-
A.if change occurs naturally in the DNA structure..
Induced mutations:-
A.change is caused by mutogens.
19.chromosomel mutations:-
A.deletion
Inversion
Translocation
Non disjuntion
Dupliation.
20.Mutogen:-
A. Any agent that cause change.
Types of mutogens:-
Physical:-radiation and heat
Chemical:-ethyl methane sulfonate.
21.DNA markers:-
A. It is a small segment of known DNA that is used in molecular biology to identify sequence of genome in a pool of unknown DNA.
22.RELP
A.restriction fragment length polymerization.
RAPD:-
Rapid amplify polymorphic DNA.
23.define translocation?
A. The transfer of part of a chromosome to a different position espercially on non homologous chromosome.
24.define lysis.and bacteriophage?
A,lysis..:-the disintegration of cell by rupture of the cell wall or membrane.
Bacteriophage:-
A virus that parasitizes a bacterium by infecting it and reproducing inside it.
25.law of independpent assortment?
A.It states that two pairs of traits are combined in a hybrid segregation of one pair is independent of the other pair of characters.
Submitted by sumanjali(DB-19)
unit II)genetic material
ReplyDelete1) SEMI CONSERVATIVE METHOD OF REPLICATION
According to this model, each strand of the two double helices formed would have one old and one new strand. This explains properly how the characters are inherited, and accepted by many.
2) CHEMICAL COMPONENTS OF DNA
DNA has three types of chemical components: phosphate, a sugar called deoxyribose, and four nitrogenous bases – adenine, guanine, cytosine and thymine.
Sugar and phosphates together known as nucleoside.
Nucleoside and nitrogen bases together known as nucleotide.
3) NUCLEOSIDE AND NUCLEOTIDE
Sugar and phosphates together known as nucleoside.
Nucleoside and nitrogen bases together known as nucleotide.
4)The types of RNA and their functions:
.There are three types of RNA.They are i.m-RNA-It is called messenger-RNA. It is transcribed from the DNA and carries the information for the protein synthesis.
ii.t-RNA-It is called transfer-RNA. It has stem loop structure. It carries amino acids to the site of protein synthesis and has anti-codon site which would be complementary to the mRNA sequence.
iii.r-RNA- It is called ribosomal-RNA. It is the site for the synthesis of proteins. It will help in attachment of the mRNA with the ribosomes.
Reply
5)Differences between DNA and RNA:
DNA:
i.It is a double stranded molecule acting as univeral genetic material.
ii.DNA contains deoxy ribose sugar molecule in it's structure.
iii.Udergoes autocatalysis and heterocatalysis.
iv.Contains Thymine as one of the nitogen base.
RNA:
i.It is a single stranded molecule which act as a genetic material in the absence of DNA molecule.
ii.RNA contains ribose sugar in it's structure.
iii.Undergoes translation to synthesize protein as a result of transcription by DNA.
iv.Contains Uracil instead of Thymine as nitrogen base.
Unit-1
ReplyDelete1.what is plasmid?
A. plasmid are present in eukaryotic organisms.They are most commonly found as small circular,double standard DNA molecules in bacteria.They are used as vectors in modern genetic engineering experiments.
A small DNA molecule within a cell uthat is separated physicallyt from a chromosomal DNA and can replicate independently.
2.what are mesosomes?
A.A specialised differentiated form of cell membrane called mesosomes is the characteristics feature of prokaryotic organisms.
The main functions of mesosomes are increasing the surface of plasma membrane that helps in the cell to carryout the respiration more efficiently.
3.what is cell theory?and it’s objectives?
A.schleiden and Schwann together formulated the cell theory.This theory however explained how new cells are formed.Rudolf Virchow first explained that cells divided and new cells are formed from pre-existing cells.
Objectives of cell theory are-
• All living organisms are composed of cells and products of cells.
• All cells arises from pre-existing cells.
4.what are the functions of cell wall?
A.It was first observed by Robert Hooke(1665)in cork tissue of oka tree.
Cell wall is a non- living rigid structureand forms an outer covering for the plasma membrane of fungi and plants.cell wall not only gives shapes to cell and protects the cell from mechanical damage and infection;it also helps in cell-to-cell interaction and act as barrier.
5 . what is nucleosome model?
A.In eukaryotic organisms the chromosomes are located inside the nucleus.The chromosome is made up of DNA and histones proteins called histones.they show positively and negatively charged reactions and they arrange compactly and produce a specialised structure called nucleosomes.They consist of eight basic proteins(h2A,h2B,h3,h4) in the form of core called octamer.Around the core the DNA wraps twice.between two nucleosomes a DNA is present called linker DNA.
Unit-2
ReplyDelete1.Differences between DNA and RNA
A.DNA:
• It is a genetic material
• It is present inside the nucleus
• It transfer the genetic material from one generation to another generation
• Thiamine is present
RNA:
• It is a non- genetic material
• Generally present in cytoplasm
• Only a few organisms it transfer the characters
• Uracil is present
2.Define nucleoside and nucleotide
A. nucleoside consists of a nitrogenous base covalently attached to a sugar (ribose or deoxyribose) but without the phosphate group.
A nucleotide consists of a nitrogenous base, a sugar (ribose or deoxyribose) and one to three phosphate groups.
3.what is semi conservative method?
A.DNA consist of two strands ,each strand used as a template for synthesis of new strands.the newly formed DNA strand consist of one parental DNA strand and one newly synthesized DNA strand.
4.define Watson and crick model.
A.watson and crick proposed that DNA is a double helical structure.It consist of two sugar phosphate backbones and held together by hydrogen bonds betweenthe nitrogen bases.
5.Define RNA .
A .RNA is a ribonucleic acid somewhat similar to DNA except presence of ribose sugar and presence of uracil in the place of thymine.
RNA is a single stranded molecule and it is present inside the cytoplasm.
Because it is a single stranded molecule chargaffs rule is not applicable.
ReplyDeleteQ1) Define cell theory and it’s objectives?
A-cell theory is one of the basic principles of biology.
The three scientists that contributed to the development of cell
theory are German Scientists Matthias Schleiden
And Theodor Schwann and .Rudolf Virchow .
This theory states that:
(i)All living organisms are composed of cells.
(ii)Cell is the structural and functional unit of life.
(iii)cells arise from the pre-existing cells.
Objectives:
(i)Describe the structure and function of the cell membrane,
Cytoplasm and the nucleus.
(ii)contrast the cell structures of prokaryotes and eukaryotes.
Q2) Define plasmid ?
A-A-plasmid is a small circular double stranded DNA molecule
Found in bacteria that can replicate independently of the
Bacterial chromosome.
Q3)Define mesosomes?
A-Mesosome is a convoluted membranous structure formed
In a prokaryotic cell by the invagination of the plasma membrane.
It helps in the secretion processes as well as in bacterial respiration.
Q4)write 4 difference between prokaryotes and eukaryotes?
A- Prokaryotes:
(i) The prokaryotes do not have a well defined
Nucleus.
(ii) Membrane bound organelles are absent.
(iii) The prokaryotic cells are smaller than eukaryotic cell and are unicellular.
(iv)They have 70s ribosome.
B- Eukaryotes:
2 / 6
(i)The eukaryotes have well defined nucleus.
(ii) Membrane Bound organelles are present.
(iii)The eukaryotic cells are larger and are multicellular.
(iv)They have 80s ribosome.
Q5)Why plasma membrane is called selectively permeable membrane?
A-Plasma membrane is called selectively permeable membrane as it allows
Only certain molecules or ions to pass through it by means of active and passive
Transport.
Q6)what are the functions of cell wall?
A-(i)The cell wall provides mechanical strength and support to the cell.
(ii) The cell wall provides a barrier to protect against plant viruses and pathogens.
. (i) It gives the cell definite shape and structure.
(iii)It also helps in osmotic regulation.
(iv)It prevents the cell from rupturing due to turgor pressure.
Q7)why mitochondria and chloroplast are called semiautonomous cell organelles?
A-The mitochondria and chloroplast are called semiautonomous cell organelles because
they have their own single circular naked DNA and 70s type of ribosome..
Q8)Why lysosomes are called suicidal bags of the cell?
A-A-The secondary Lysosomes bursts during starvation and releases the undigested food in protoplasm as they kill themselves they are called suicidal bags.
Q9) Difference between Heterochromatin and Euchromatin?
A-Heterochromatin:
-(i)Heterochromatin is the darkly stained part of the chromosome.
(ii)It is more condensed.
(iii)It contain inactive genes.
(iv)Adenine and Thymine is rich in Heterochromatin.
Euchromatin:
(i)Euchromatin is the light stained part of chromosome.
3 / 6
(ii)It is less condensed.
(iii)It contain active genes
(iv)Guanine and cytosine are rich in Euchromatin.
submitted by:
Namita
DB- 10.
Q10)Define Nucleosome Model?
ReplyDeleteA-A bead like structure of chromatin fibres each one composed of 4
Pairs of basic protein called histone i.e.H2A,H2B,H3,H4.on which DNA is
Coiled around twice. The 2 Nucleosomes are connected by the DNA called linker DNA.
This is called Nucleosome Model.
Q11)Define transduction and conjugation?
A-Transduction-The process by which foreign DNA is introduced into a cell
by vector..
Conjugation -The process of transfer of genetic material between bacterial cell
through direct contact.
Q12)Define nucleotide and nucleoside?
A -Nucleotide:
Nucleotide is a organic molecule that is the building blocks of DNA and RNA.
It consists of nitrogenous base,pentose sugar and phosphate group.
Nucleoside:
Nucleoside is the nitrogenous base that is bound to the pentose sugar.
Q13) Difference between DNA and RNA?
A- DNA:
(i)Double stranded molecule with a long chain of nucleotides.
(ii)It consists of deoxyribose sugar and phosphate backbone.
(iii)The four nitrogenous bases of DNA is adenine, guanine, thymine and cytosine.
(iv)It is meant for the storage of genetic material.
RNA:
(i)single stranded molecule with a short chain of nucleotides.
(ii)It consists of ribose sugar and phosphate backbone.
(iii)The four nitrogenous bases of RNA is adenine , guanine,uracil and cytosine.
(iv)It is meant for expression of stored genetic information.
Q14) Define Test cross and Back cross?
4 / 6
A-Test cross: I
The cross made between F1 hybrid with its recessive parents.
Back cross:
The cross made between F1 hybrid with anyone of its parents.
Q15)Define linkage and crossing over?
A-linkage:
The tendency of genes to remain together in the same chromosome is called
Linkage.
Crossing over:
The exchange of genetic material between the non- sister chromatids
Of homologous chromosomes during meiosis is called crossing over.
Q16)Differentiate between complete and incomplete linkage?
A-In complete linkage the genes are completely linked, inherited in a set and
No recombination occurs whereas in incomplete linkage the genes are not
Completely linked and recombination may occur.
submitted by:
Namita
DB-10
Unit-3
ReplyDelete1.What is Test cross and back cross?
A.Test cross:the cross between F1 progeny and recessive homozygous parent is called test cross .(Tt×tt).
Back Cross:if F1 hybrid crossed with one of its parents is called back Cross.(Tt×tt or Tt×TT).
2.Define law of independence.
A.Mendels law states that when two alles of inherited pair is heterozygous,then the alle which express the character is called dominant and another which does not express is called recessive.the recessive will not express because of the suppressing dominant allele
3.Define linkage and crossing over.
A.3: Itis the tendency of DNA sequence that are close together on a chromosome is called linkage.
Crossing over:The exchange of chromosomal between two non-sister chromatids is called crossing over . Recombinations occurs during meiosis because of crossing over .the need of crossing over is to provide genetic variations during meiosis.
4. Define complete linkage and incomplete linkage.
A .In complete linkage two loci are close together and these are never seperated by crossing over.In this type the Recombinations will be less.
Incomplete linkage:the genes are loosely linked on a chromosomes and in this type the Recombinations percentage will be high.
5.what is semi conservative method ?
A. Semiconservative replication would produce two copies that each contained one of the original strands and one new strand. Conservativereplication would leave the two original template DNA strands together in a double helix and would produce a copy composed of two new strands containing all of the new DNA base pairs.
Unit-3
1.What is Test cross and back cross?
A.Test cross:the cross between F1 progeny and recessive homozygous parent is called test cross .(Tt×tt).
Back Cross:if F1 hybrid crossed with one of its parents is called back Cross.(Tt×tt or Tt×TT).
2.Define law of independence.
A.Mendels law states that when two alles of inherited pair is heterozygous,then the alle which express the character is called dominant and another which does not express is called recessive.the recessive will not express because of the suppressing dominant allele
3.Define linkage and crossing over.
A.3: Itis the tendency of DNA sequence that are close together on a chromosome is called linkage.
Crossing over:The exchange of chromosomal between two non-sister chromatids is called crossing over . Recombinations occurs during meiosis because of crossing over .the need of crossing over is to provide genetic variations during meiosis.
4. Define complete linkage and incomplete linkage.
A .In complete linkage two loci are close together and these are never seperated by crossing over.In this type the Recombinations will be less.
Incomplete linkage:the genes are loosely linked on a chromosomes and in this type the Recombinations percentage will be high.
5.what is semi conservative method ?
A. Semiconservative replication would produce two copies that each contained one of the original strands and one new strand. Conservativereplication would leave the two original template DNA strands together in a double helix and would produce a copy composed of two new strands containing all of the new DNA base pairs.
Unit-4
ReplyDelete1.Define acclimatization.
A.Adjustment of introduce plants in a new locality and changed climatic conditions.such plants are disease resistance due changes environment but
adulterant seeds.
2.Define emasculation,bagging?
A.Emasculation:after selecting an undesirable parent they are underwent selling inorder to minimise the heterozygosity .the removal of stamens from a bisexual flowers before anthesis called Emasculation.
Bagging: immediately after Emasculation the female flowers are covered with the help of a polythene bag ,this prevents unnecessary cross-pollination from female parents .
3.Define introduction and name any two achievements.
A.The process of introducing high yielding varieties of plant from their growing locality into a new locality called introduction.
It is the easiest method to transfer the plants from one place to another place.
Merits:-
• It is the easiest,simplest and quickest method.
• No need of scientific knowledge
• Introduced plants can be subjected to other breeding techniques for better results.
4.Define mass,purline and clonal selection.
A . Mass selection:occurs in cross pollinated plantts.this can be done in open or mixed field .they shows morphological characters .in this method there no need of scientific knowledge and and there is no control over the cross pollination.
Pureline selection: selecting desirable homozygous individual from the mixed population and selfing the same in next generations to release a new variety that occurs by self pollination.
Clonal selection:the selection of vegitative propagation(clones)from a single plant called clonal selection.
5.Define hybridization and mention any two objectives
A.hybridisation is a plant breeding method that is produced new varieties of cropin which two or more plants of genotypes are crossed.the main focus is to produce a desirable characteristics plant variety.
Objectives:
• High hybrid vigorousity plants obtained
• Disease resistance plants occur
ReplyDeleteQ17)Define plant breeding and mention any two objective s?
A-Plant breeding:
The phenomena of development of new varieties of plants possessing
Desirable characters from the already existing varieties is called plant breeding.
Objectives:
(i)To obtain high yielding and disease resistant variety.
(ii)To improve the quality ,size,shape,colour,taste and durability of the product.
Q18)Define Acclimatization?
A-The phenomenon in which the introduced plants adjust to the new
Environmental conditions called Acclimatization.
Q19)Define Hybridization? Mention any two objectives?
A-Hybridization :
The process of interbreeding between individuals of different species
Or genetically divergent individuals from the same species is called Hybridization.
5 / 6
Objectives:
(i)The chief objective of hybridization is to create variations.
(ii)To produce and utilize hybrid vigour.
Q20)Define mutagen? Name two types of agents?
A-The mutagens are the agents that causes changes in the chromosomes.
Types of agents:
(i) Physical agents : e.g. UV ,X-rays etc.
(ii) Biological agents : e.g. viruses, bacteria etc.
Q21)Define somaclonal variations?
A-The genetic variation found in the in-vitro cultured cells are collectively
Referred as somaclonal variations.
Q22)Mention different types of chromosomal mutation?
A-(i) Deletion
(ii)insertion
(iii)inversion
(iv)Translocation
Q23)Expand RFLP and mention it’s objectives?
A-Restriction fragment length polymorphism.
Objectives:
(i)It is extensively used for genome analysis.
Q24)Define DNA markers and it’s applications?
A-A-It is the small segment of known DNA that is used in molecular biology and
Biotechnology to identify the sequence of genome in a pool of unknown DNA.
Application s:
The DNA markers can be used for constructing genetic linkage maps.
The DNA markers are useful in the study of crop evolution.
Q25)Define emasculation and bragging?
A-Emasculation:
The process of removal of anthers of flower in order to prevent self pollination
6 / 6
Is called emasculation.
Bragging:
A-The process in which the emasculated flowers have to be covered with a bag of suitable
Size made of butter paper to prevent contamination of its stigma with unwanted
Pollen is called bagging.
submitted by:
Namita
DB-10
DEAR NAMITA
DeleteQUESTION IS BAGGING NOT BRAGGING, PLEASE CHECK BEFORE POSTING.
Unit-5
ReplyDelete1.Distinguish spontaneous mutation from induced mutation.
A.Sponatenous mutation:change occur naturally in a DNA structure and it is called spontaneous mutation.
Induced mutation:change caused by mutagens
2.Mention different types of chromosomal mutation.
A.1. deletion
2.inversion
3.translocation
4.disjunction
5.dulpication
3.Define mutagen and name any two types of agents.
A.Any environmental agents that significantly increase the rate of mutation above the spontaneous rate.
Non-disjunction:fail to separate during meiosis.
Point mutation:change of a single nucleotide includes deletion.inversion etc.
4.Explain RFLP and mention it’s objectives.
A.RFLP: restriction fragmented length polymorphism.
Objectives:
Establish genetic relationships between sexually incomaprable crop plants.
5.Explain RAPD and it’s objectives.
A.RAPD: rapid amplified polymorphic DNA.
Objectives:
Used to dinstiguish between variety based on different DNA sequence.
Unit1- Cell Biology
ReplyDelete1.what is plasmid. mention its role?
A.-A small,circular,single stranded, extra chromosomal DNA present in bacteria.
-It replicate independently.
-Plasmids are much used in the laboratory m
manipulation of genes.
2.cell theory and objectives
A.-M.J Schleiden and Theodor schwann
- All the living organisms are composed of one are more cells.
-The cell is the basic structural and functional unit of organism
-Cells arise from pre-existing cells.
3.Why mitochondria and chloroplast are semi autonomous cells?
A.-In eukaryotic cell both mitochondria and cloroplast have their own DNA and ribosomes.
-Mitochondria is semi autonomous because it is having its own DNA and replicate its own they can replicate inpendently.
-They have their own protein synthesising machinery.
4.suicidal bags.
A.-Lysosomes are called suicidal bags.
-They contain digestive enzymes.
-They may help in the autodigestion of the cell itself.
-It main function is protects the body from viruses and bacteria.
5.Nucleosome model.
A.-Nucelosome is the basic unit of DNA packingin eukaryotes.
-Consisting of a segment of DNA wound in sequence around 8 histone protein cores.
-This structure is often compared to thread wrapped around a spool.
Ch.Preethi
DZ-36
Unit 2- GENETICS
ReplyDelete1.chemical components of DNA
A.-DNA is made up of molecule called
Nucleotide.
-Each nucleotide contains phosphate group,
Sugar group, nitrogen base.
-The 4types of nitrogen bases are adenine
thymine,guanine,cytoine.
-The oder of these bases determines DNA's
introduction or genetic code.
2.Define nucleotide and nucleoside.
A.Nucleotide- Nitrogen base+sugar group.
Nucleoside-Nitrogen
base+sugar4group+phosphate group
3.semiconservation model.
A.- semiconservative model or DNA sequencing
Which is the process of determining the
Precise order of nucleotides with DNA
-It includes any method of technology i.e.,
Used to determine the order of 4 bases adenine, guanine, thymine, cytosine in strand
of DNA.
4.Define clover leaf method.
A.-The clover leaf model of tRNA is a model
that depicts the molecular structure of
tRNA.
-The model revealed that the chain of tRNA
Consists of two ends,sometimes called
"Business ends" and three arms.
5. Watson and crick.
A.They both worked together on studying the
Structure of DNA.
-DNA means deoxy ribonucleic acid.
- It is a double helical structure.
- They won Nobel Prize for their discovery.
Ch.Preethi
DZ-36.
1) Cell theory and it’s objectives?
ReplyDeleteAns:- However, many other scientists like Rudolf Virchow contributed to the theory. It was an important step in themovement away from spontaneous generation. The three tenets to the cell theory are as described below: All living organisms are composed of one or more cells.cells are the basic unit of structure and function in living things.all cells are producer from other cells .
2) Coupling and repulsion theory?
Ans:- Coupling refers to the case where dominant alleles are on the same homologue chromosome and both recessive alleles are on the other homologue chromosome. ... Repulsionrefers to the case where each homologous chromosome has one dominant and one recessive allele from the two genes. Thus, the parental gametes are Ab and Ab.
3) Define plasmid ?
Ans:- a genetic structure in a cell that can replicate independently of the chromosomes, typically a small circular DNA strand in the cytoplasm of a bacterium or protozoan. Plasmids are much used in the laboratory manipulation of genes.
4)what is mesosome ?
Ans:-meosomes or chondrioids are folded invaginations in the plasma membrane of bacteria that are produced by the chemical fixation techniques used to prepare samples for electron microscopy.
5)Difference between prokaryote and eukaryotes?
Ans:- Eukaryotic cells contain membrane-bound organelles, including a nucleus.Eukaryotes can be single-celled or multi-celled, such as you, me, plants, fungi, and insects. Bacteria are an example of prokaryotes. Prokaryoticcells do not contain a nucleus or any other membrane-bound organelle.
6) fluid mosaic model?
Ans:- The fluid mosaic model describes the structure of the plasma membrane as a mosaic of components —including phospholipids, cholesterol, proteins, and carbohydrates—that gives the membrane a fluid character. Plasma membranes range from 5 to 10 nm in thickness.
7) selectively permeable membrane?
Ans:- One important feature of plasma membranes is that they are selectively permeable. Selectively permeable means that substances can pass through the cell membrane but other substances can't. Sometimes this selectivity is passive. It does not require the cell to do any work.
8) functions of cell wall?
Ans:- The plant cell wall is composed of cellulose. Cellulose is a structural carbohydrate and is considered a complex sugar because it is used in both protection and structure. The plant cell wall consists of three layers. Each layer has its own unique structure and function.
9) suicidal bags?
Ans:- These enzymes also digest any kind of worn out cell organelles or foreign materials like bacteria or viruses that enter the cell. Thus, lysosomes help in keeping the cell clean. ... Hence, lysosomes are called suicide bags of the cell.
10) difference between euchromatin and heterochromatin?
Ans:- Chromatin has two forms:euchromatin and heterochromatin. ...Euchromatin contains less DNA whileheterochromatin contains more DNA.Euchromatin is early replicative whileheterochromatin is late replicative.Euchromatin is found in eukaryotes, cells with nuclei, and prokaryotes, cells without nuclei.
Submitted by
M.ravi chandana reddy
DB-11
DEAR DB-11-
Delete1. FIRST WRITE YOUR NAME PROPERLY.
2. WRITE THE QUESTIONS PROPERLY NOT IN SHORT FORM.
11) nucleosome model?
ReplyDeleteAns:- A nucleosome is a basic unit of DNA packaging in eukaryotes, consisting of a segment of DNA wound in sequence around eight histone protein cores. This structure is often compared to thread wrapped around a spool.
12) define transduction ?
Ans:- 1 : the action or process of converting something and especially energy or a message into another form. 2 : the transfer of genetic material from one organism (as a bacterium) to another by a genetic vector and especially a bacteriophage .
13) conjugation?
Ans:- Conjugation is the process by which one bacterium transfers genetic material to another through direct contact. During conjugation, one bacterium serves as the donor of the genetic material, and the other serves as the recipient. The donor bacterium carries a DNA sequence called the fertility factor, or F-factor.
14) Translation?
Ans:- In molecular biology and genetics, translation is the process in which ribosomes in the cytoplasm or ER synthesize proteins after the process of transcription of DNA to RNA in the cell's nucleus. ... In translation, messenger RNA (mRNA) is decoded in a ribosome to produce a specific amino acid chain, or polypeptide.
15) Define lysis and bacteriophage?
Ans:-lysis- the disintegration of a cell by rupture of the cell wall or membrane
Bacteriophage:- A bacteriophage, also known informally as a phage, is a virus that infects and replicates within Bacteria and Archaea. The term was derived from "bacteria"
16) define nucleotide and nucleoside ?
Ans:- nucleotide - Nucleotides are organic molecules that serve as the monomer units for forming the nucleic acid polymers deoxyribonucleic acid and ribonucleic acid, both of which are essential biomolecules within all life-forms on Earth.
Nucleoside:- a compound (e.g. adenosine or cytidine) consisting of a purine or pyrimidine base linked to a sugar.
17)Watson and Crick model?
Ans:- Watson-Crick Structure of DNA. Deoxyribonucleic Acid (DNA) is a double-stranded, helical molecule. It consists of two sugar-phosphate backbones on the outside, held together by hydrogen bonds between pairs of nitrogenous bases on the inside.
18) difference between dna and rna?
Ans:- DNA is a long polymer with deoxyriboses and phosphate backbone. Having four different nitrogenous bases: adenine, guanine, cytosine and thymine. RNA is a polymer with a ribose and phosphate backbone. Four different nitrogenous bases: adenine, guanine, cytosine, and uracil.
19)test cross and back cross?
Ans:-test cross- In genetics, a test cross, first introduced by Gregor Mendel, is used to determine if a group exhibiting a dominant trait is homozygous or heterozygous for that trait. More simply put, test crosses determine the genotype of an individual with a dominant phenotype.
Back cross- Backcrossing is a crossing of a hybrid with one of its parents or an individual genetically similar to its parent, in order to achieve offspring with a genetic identity which is closer to that of the parent.
20)law of independent assortment?
Ans:- The Principle of Independent Assortment describes how different genes independently separate from one another when reproductive cells develop.
Submitted by
M.Ravi chandana reddy
DB-11
21) law of dominance / segregation ?
ReplyDeleteAns:- Law of segregation. During gamete formation, the alleles for each genesegregate from each other so that each gamete carries only one allele for each gene. Law of independent assortment. Genes for different traits can segregate independently during the formation.
22) different types of chromosomal mutations?
Ans:- A mutation involving a long segment of DNA. These mutations can involve deletions, insertions, or inversions of sections of DNA. In some cases, deleted sections may attach to other chromosomes, disrupting both the chromosomes that loses the DNA and the one that gains it. Also referred to as a chromosomal rearrangement.
23)what are somaclonal variations ?
Ans:- Somaclonal variation is the variation seen in plants that have been produced by plant tissue culture. Chromosomal rearrangements are an important source of this variation.
24)what is emasculation and bagging ?
Ans:- emasculation - The removal of the anthers of a flower in order to prevent self-pollination or the undesirable pollination of neighbouring plants.
Bagging- This technique is an important part of theplant breeding programme as it ensures that pollen grains of only desirable plants are used for fertilization of the stigma to develop the desired plant variety.
25) define clover leaf model?
Ans:- The Cloverleaf model of tRNA is amodel that depicts the molecular structure of tRNA. The model revealed that the chain of tRNA consists of two ends, sometimes called "business ends" and three arms.
21) law of dominance / segregation ?
ReplyDeleteAns:- Law of segregation. During gamete formation, the alleles for each genesegregate from each other so that each gamete carries only one allele for each gene. Law of independent assortment. Genes for different traits can segregate independently during the formation.
22) different types of chromosomal mutations?
Ans:- A mutation involving a long segment of DNA. These mutations can involve deletions, insertions, or inversions of sections of DNA. In some cases, deleted sections may attach to other chromosomes, disrupting both the chromosomes that loses the DNA and the one that gains it. Also referred to as a chromosomal rearrangement.
23)what are somaclonal variations ?
Ans:- Somaclonal variation is the variation seen in plants that have been produced by plant tissue culture. Chromosomal rearrangements are an important source of this variation.
24)what is emasculation and bagging ?
Ans:- emasculation - The removal of the anthers of a flower in order to prevent self-pollination or the undesirable pollination of neighbouring plants.
Bagging- This technique is an important part of theplant breeding programme as it ensures that pollen grains of only desirable plants are used for fertilization of the stigma to develop the desired plant variety.
25) define clover leaf model?
Ans:- The Cloverleaf model of tRNA is amodel that depicts the molecular structure of tRNA. The model revealed that the chain of tRNA consists of two ends, sometimes called "business ends" and three arms.
Submitted by
M.ravi chandana reddy
DB 11
Unit-1
ReplyDelete1.What is plasmid?
A plasmid is a small DNA molecule with in a cell i.e; physically separated from a chromosomal DNA and can replicate independently.They are most commonly found as small circular, double stranded DNA molecule in bacteria
2.what is mesosomes?
Mesosomes are the invaginated structures formed by the localised infoldings of the plasma membrane.The invaginated structures comprise of vesicles,tubules of lamellar whorls.
3.Differences b/w eukaryotic & prokaryotic cell.
Eukaryotic cell:
-These cells are mostly multicellular.
-Nuclear membrane and nucleolus are present.
-They contain multiple linear with histones.
-They expressed individually.
Prokaryotic cell:
-These are mostly unicellular.
-True nucleus is absent.Nucleus lack nuclear membrane and nucleolus.such nucleus is called NUCLEOID.
-Usually single circular with out histones.
-Expressed in groups called operons.
4.What is fluid mosaic model?
The fluid mosaic model explains various observations regarding the structure of functional cell membranes.According to this model there is a lipid bilayer in which the protein molecules are embedded.The lipid bilayer gives fluidity and elasticity to the membrane.
5.What are the functions of cell wall?
-They cell wall gives the plant its actual shape.
-It acts as a gate keeper because it determines what can come in and out of the cell inorder to keep the cell protected.
-They cell wall provides the mechanical strength and support.It also controls the direction of cell growth.
-The cellwall sends signals for the cell to cell enter the cycle inorder to divide and grow.
Name marchipoyanu mam .....I'm S.Triveni DB-37....unit 1 pampanu mam....
ReplyDelete1)Define monohybrid cross and dihybrid cross
ReplyDeleteAns)Monohybrid cross:
The cross is made between 2 induviduals differ in one character.
Dihybrid cross:
The cross is made between 2 induviduals differ in two contrasting character.
2)define test cross and back cross
Ans)Test cross:
Cross f1hybrid with its recessive parent.
Back cross:
Cross between f1 hybrid with any one of its parents.
3) define PLASMIDS:
Ans)A gentic structure in a cell that can replicate independently of the chromosome Typically small circular DNA strands in the cytoplasam of the bacterium.
4)MESOSOMES:
Ans)An organelle of bateria that appears as an invagination of plasma membrane and funtion either in DNA replication and
cell division or excretion of enzyme.
5)what are SUICIDAL BAGS:
Ans)Lysosomes are called as suicidal bags. They are filled with digestive enzyme. These enzymes also digest any kind of worn out cell organelles or foreign materials bacteria or virus that enter the cell.
6)NUCLEOSOME MODEL:
Ans) A nucleosome is a basic unit of DNA packaging in eukaryotes,consisting of a segment of DNA wound in sequence around eight histone protien cores. This structure often compared to thread wrapped around a pool.
7) define CELL THEORY:
Ans) Living organisms are made up of cells.Cells are basic structural and functional unit of all organisms.
Cells come from pre- existing cells.
8)Define Law of independent assortment?
Ans) It states that the two pairs of traits are combined in a hybrid segregation of one pair is independent of the other pair of characters.
9)Define law of dominance?
Ans)The law of dominance "when two alleles of an inherited pair is heterozygous,then the allele that is expressed is dominant whereas the allele that is not expressed is recessive.
10)Define euchromatin and heterochromatin
Ans)euchromatin:light staining part of DNA. It is generally active and loosely coiled.
Heterochromatin:darkly stained portion of chromatin.dna is densely coiled and genetically inert.
1)Define monohybrid cross and dihybrid cross
ReplyDeleteAns)Monohybrid cross:
The cross is made between 2 induviduals differ in one character.
Dihybrid cross:
The cross is made between 2 induviduals differ in two contrasting character.
2)define test cross and back cross
Ans)Test cross:
Cross f1hybrid with its recessive parent.
Back cross:
Cross between f1 hybrid with any one of its parents.
3) define PLASMIDS:
Ans)A gentic structure in a cell that can replicate independently of the chromosome Typically small circular DNA strands in the cytoplasam of the bacterium.
4)MESOSOMES:
Ans)An organelle of bateria that appears as an invagination of plasma membrane and funtion either in DNA replication and
cell division or excretion of enzyme.
5)what are SUICIDAL BAGS:
Ans)Lysosomes are called as suicidal bags. They are filled with digestive enzyme. These enzymes also digest any kind of worn out cell organelles or foreign materials bacteria or virus that enter the cell.
6)NUCLEOSOME MODEL:
Ans) A nucleosome is a basic unit of DNA packaging in eukaryotes,consisting of a segment of DNA wound in sequence around eight histone protien cores. This structure often compared to thread wrapped around a pool.
7) define CELL THEORY:
Ans) Living organisms are made up of cells.Cells are basic structural and functional unit of all organisms.
Cells come from pre- existing cells.
8)Define Law of independent assortment?
Ans) It states that the two pairs of traits are combined in a hybrid segregation of one pair is independent of the other pair of characters.
9)Define law of dominance?
Ans)The law of dominance "when two alleles of an inherited pair is heterozygous,then the allele that is expressed is dominant whereas the allele that is not expressed is recessive.
10)Define euchromatin and heterochromatin
Ans)euchromatin:light staining part of DNA. It is generally active and loosely coiled.
Heterochromatin:darkly stained portion of chromatin.dna is densely coiled and genetically inert.
S.Triveni
ReplyDeleteDB-37
Unit-2
1.Nucleotide and Nucleoside.
Nucleotide:consists of a nitrogenous base a sugar and one to three phosphate groups.
Nucleotide=sugar+base+phosphate
Nucleoside:consists of a nitrogenous base covalently attached to a sugar but with out the phosphate group.
Nucleoside=sugar+base.
2.Watson and cricks model.
Watson and cricks combined the physical and chemical data and proposed a double helix model for DNA molecule.Accordind to this model consists of two strands which are connected together by hydrogen bonds and helically twisted.Thus strand of DNA molecule is a polymer of four nucleotides i.e,A,G,T,C.
3.Differences b/w DNA and RNA.
DNA:
-It is usually occurs inside nucleus and some cell organelles.
-It is double stranded with expections of some viruses.
-DNA contains over a million nucleotides.
-The sugar portion of DNA is 2-deoxyribose.
RNA:
-Very little RNA occur inside the nucleus.most of it is found in the cytoplasm.
-It is single stranded with expection of some viruses.
-Depending on the type RNA contains 70-12000 nucleotides.
-The sugar portion of RNA is ribose.
4.Clover leaf model:
The clover leaf model of tRNA is a model that depicts the molecular structure of tRNA.The model revealed that the chain of tRNA consists of 2 ends, sometimes called "Business ends" and three arms.Two of the arms have a loop,D-loop and C-loop with a ribosome recognition site.The third arm known as " Variable arms" has a stem with optional loop.
5.Semi conservative model:
Semi conservative replication would produce 2copies that each contained on of the original strand and new strand.Conservative replication would leave the two original template DNA strands together in a double helix and would produce a copy composed of 2 new strands containing all of the new DNA base pairs.
S.Triveni
ReplyDeleteDB-37
Unit-3
1.Coupling theory:
If two alleles such as 'AB' come from the same parent(AABB×aabb) then they will enter into the same gamates and transmit together.This is called coupling theory.
Repulsion theory:
When the same alleles (A&B) come from the different parents(AAbb×aaBB) then they will enter into different gamates at the time of gametogenesis. This is called repulsion theory.
2.law of dominance:
"when two alleles of an inherited pair is heterozygous,then the allele that is expressed is dominant whereas the allele that is not expressed is recessive".
3.Test cross:
Cross made b/w F1 hybrid with its recessive parent.
Back cross:
If a cross is made b/w F1 hybrid with any one of its parents.
4.Law of independent assortment:
The law of independent assortment is a principle of inheritance that each heritable allele is inherited independently of one another.
5.Linkage:
Tendency of gene to remain together in the same chromosome.
Crossing over:
Exchange of segments b/w non-sister chromatids of homologous chromosomes.It increase visibility of forming new gene combinations.
S.Triveni
ReplyDeleteDB-37
Unit-4
1.plant breeding:
It is a science based on principles of genetics and cytogenetic.It aims at improving the genetic make up of the crop plants.Improved varieties are developed through plant breeding.
Objective:
Higher yield
Disease resistance
Early to mature
Better quality.
2.Acclimatisation:
The newly introduced varieties has to adapt or adjust itself to the changed climatic conditions. This adjustment is called acclimitization.
3.Hybridization:
The mating or crossing of two plants or lines of dissimilar genotype is known as "hybridization".
Objectives:
To create genetic variation
Seggregation and recombination produce many new gene combinations.
4.Emasculation:
Removal of male sex organs or killing that part of the flower without any disturbances to female reproductive organ is known as emasculation.
Bagging:
The flower is enclosed in suitable bag to prevent random cross pollination.
5.Mass line selection:
It can be defined as selection of a number of phenotypically superior seeds from the field population harvesting and bulking their produce together for sowing the next year's crop and process is repeated till desirable characters are achieved.
Pure line selection:
It can be defined as the process of isolating a desirable homozygous individuals from the mixed population and multiplying the same without contamination to release as a new variety.
Clonal selection:
A variety that is propagated vegetative from single parent is called clone. Selection of Desirable clones from the mixed population of vegetative propagated crops called clonal selection.
S.Triveni
ReplyDeleteDB-37
Unit-5
1.Mutagens:
The physical or chemical agent significantly increases the mutation.
Physical mutagens:radiation and heat
Chemical mutagens:basic analogs, alkylating agents, metals, deaminating agents, intercalating agents
2.RFLP-Restriction frangemt length polymorphism.
Objectives:
1.It is extensively used in genome analysis.
2.The variation is the restriction DNA fragment lengths between individuals of a species
3.Inbreed lines:
The Mating of individuals or organisms that are closely related through common ancestry.
4.Soma clonal variations:
The genetic variations found in the invitro cultured cells are collectively referred as somaclonal variation .
5.chromosomal theory;
These theory was proposed by Morgan. According to him genes are present in the pairs of chromosomes and the chromosomal substances binds these linked genes together during the process of inheritance.The degree of linkage is determined by distance of the gene,if the genes are closer the linkage is very strong.
N. Prathyusha.
ReplyDeleteDB-27 .
Submitting assignment ,semester -5 cell biology, genetic and plant breeding..
Unit-1-Cell biology.
1.Plasmid:- A plasmid is a small DNA molecule within a cell that is physically separated from a chromosomal DNA and can replicate independently. They are most commonly found as small circular, double stranded DNA molecules in bacteria, however, plasmids are sometimes present in Archie and eukaryotic organisms .
2.semi autonomous cell organelles :-*Nucleus is an autonomous organelle in the cell.
*Mitochondria and plastids are semi autonomous organelles.
*Autonomous organelles are those which have the command of their own all over .
*semi autonomous organelles are dependent on autonomous organelles for some work.
3.suicidal bags:-Lysosomes are called suicidal bags. They are present only in animal cells. These are the digestive bodies which contains digestive enzymes. They are called suicidal bags because when there is lack of oxygen and food they break to release the enzymes which digest the whole cell.
4.Nucleosome model:-A nucleosome is a basic unit of DNA packaging in the eukaryotes, consisting of a segment of DNA wound in sequence around eight histones protein cores. This structure is often compared to thread wrapped around a spool.
5.why plasma membrane is called selectively permeable membrane :-It is because, plasma membrane allows some material to pass through it while on the same time it blocks other materials from entering through it. In other words it selects materials that can enter the cell that's the reason it is called selectively permeable membrane.
N. Prathyusha.
ReplyDeleteDB-27.
Unit-2 Genetics.
1.components and chemical composition of DNA :-DNA has 3types of components phosphate, a sugar called deoxyribose and four nitrogen bases adenine, guanine ,cytosine, thymin. 2 of the bases adenine, guanine have a double ring structure characteristic of a type of chemical called purine .
2.Nucleoside:-A compound (such as guanosine or adenosine) that consists of a purine or pyramidine base combined with deoxyribose or ribose and is found especially in DNA or RNA.
Nucleotide :-A compound consisting of a nucleotide linked to a phosphate group nucleotide from the basic structural unit of nucleic acids such as DNA.
3.Semi conservative method of replication :-It would produce two copies that each contain one of the original strands and one new strand. Conservative replication would leave the two original template DNA strands together in a double helix and would produce a copy composed of two new strands containing all of the new DNA base pairs.
4.watson and crick :-They proposed double helix structure of DNA they also received a noble price in1962.
DNA is a double standard helical molecule. It consists of 2sugar phosphate Back bones on the outside held together by hydrogen bond between pairs of nitrogenous bases on inside.
5.Any four differences between DNA and RNA:-
*DNA contains the sugar deoxyribose while RNA contains the sugar ribose only difference between ribose and deoxyribose in that ribose has one more -OH group than deoxyribose, which has-H attached to the second carbon in the ring.
*DNA is a double stranded molecule while RNA is a single stranded molecule.
*DNA is a stable under alkaline conditions while RNA is not stable.
*DNA and RNA perform different functions in humans. DNA is responsible for storing and transferring genetic information while RNA directly codes for amino acid and as a acts as a messenger between DNA and ribosomes to make proteins.
Unit 1 Db 43
ReplyDelete1.Plasmi?
It is a circular ring like structure
That can replicate independently of chrmosomes
2.mesomes?
They are finger like projections arises from plasma memrane they act as respiratory substrate
3.semi autosomal cell organals?
They are single circular naked Dna and 70s ribosomes
4.power house of the cell?
The mitochondria is power house of the
Cell has it controls the functions of the cell
5.cell brain?
Nuclease is called cell brain it contain chromatin it devlops into chrmosomes
ANDHRA LOYOLA COLLEGE (Autonomous) VIJAYAWADA-08
ReplyDeleteII B. Sc – BOTANY SYLLABUS- THEORY
PAPER – III; SEMESTER – III
(Paper – III: Plant Taxonomy and Embryology)
UNIT - I: Introduction to Plant Taxonomy
1. Fundamental components of Taxonomy (Identification, nomenclature, classification types and phylogeny)
2. Salient features and comparative account of Bentham & Hooker and Engler & Prantl classification
3. Role of Chemotaxonomy, Cytotaxonomy and Taximetrics in relation to Taxonomy
UNIT – II: Taxonomic Resources
1. Nomenclature and Taxonomic resources: An introduction to International code of Botanical Nomenclature; Principles, Rules and Recommendations, Herbaria, Botanical Gardens of the World, Botanical Keys.
2. Systematic study and economic importance of plants belonging to the following families Annonaceae, Caparidaceae, Rutaceae, Curcurbitaceae, and Apiaceae
UNIT – III: Systematic Taxonomy
1. Systematic study and economic importance of plants belonging to the following families Asteraceae, Sapotaceae, Asclepiadaceae, Euphorbiaceae, Lamiaceae, Amaranthaceae, Orchidaceae and Poaceae.
UNIT – IV: Embryology
1. Introduction: History and Importance of Embryology.
2. Microsporogenesis : Microspore and development of male gametophyte.
3. Palynology : Principles and applications
4. Megasporogenesis; Monosporic (Polygonum) Bisporic (Allium) and Terasporic (Adoxa) types of female gametophyte/embryo sac development.
UNIT – V: Embryogeny
1 Embryo – Development of Monocot and Dicot embryo (with one example)
2 Polyembryony and Apomixis – and outline.
3 Endosperm –Nuclear, Cellular and Helobial endosperm.
Submitted by : P.SANDHYA DB-1
ANDHRA LOYOLA COLLEGE (Autonomous) VIJAYAWADA-08
ReplyDeleteII B. Sc – BOTANY SYLLABUS, SEMESTER – IV,
PAPER – IV
(Plant Physiology and Metabolism
UNIT – I: Plant – Water relations
1. Importance of water to plant life, physical properties of water
2. Diffusion, imbibition and osmosis; Concept of water potential
3. Absorption, transport of water, ascent of sap
4.Transpiration – Structure of stomata, mechanism of stomata opening and closing and factors effecting transpiration.
UNIT – II: Mineral nutrition and Enzymes
1. Mineral Nutrition : Essential macro and micro mineral nutrients and their role, mineral nutrients uptake (active and passive), deficiency symptoms of nutrients
2. Nitrogen cycle – Biological nitrogen fixation
3. Enzymes: Nomenclature, characteristics and enzyme action (Lock and Key theory and Induced fit theory)
UNIT – III: Photosynthesis
1. Photosynthesis: Photosynthetic pigments, absorption and action spectra; Red drop and Emerson enhancement effect, concept of two photosystems, mechanism of photosynthetic electron transport and evolution of oxygen, photophosphorylation, carbon assimilation pathways: C3, C4, and CAM.
2. Photorespiration.
3. Translocation of organic substances- Mechanism of phloem transport, source-sink relationships.
UNIT: IV: Plant Metabolism
1. Respiration: Aerobic and Anaerobic, Krebs cycle, electron transport system, mechanism of oxidative phosphorylation, Pentose phosphate pathway.
2. Lipid Metabolism : Structure and functions of lipids, conversion of lipids to carbohydrates, Beta-oxidation
3. Types of phosphorylation: ATP – Synthesis (Substrate level, Oxidative and Photophosphorylation)
UNIT – V: Growth and Development
1. Growth and Development : Definition, Synthesis and physiological effects of phytohormones – auxins, gibberellins, cytokinins, ABA, ethylene
2. Physiology of flowering and photoperiodism, role of phytochrome in flowering.
3. Stress Physiology: Concept and plant responses to water and temperature stresses.
Submitted by :P.SANDHYA DB-1
Unit:5 Db 43 jagadeesh kumar
ReplyDelete1.Define Rapd?
Rapid amplified polymorpic dna
2.Rflp ?
Restriction fragment length poly morphism
3.Dna markers?
Genes or dna seqence with known location that can be used to identify individual or species
N. Prathyusha.
ReplyDeleteDB-27
Unit-3 Mendilian inheritance
1.Define law of Dominance :-It is also called as law of segregation. This law is proposed by G. J Mendel. It states that when 2alleles of an inherited pair is heterozygous then, the allele that is expressed is dominant where as the allele that is not expressed is recessive .
2.Test cross:-The cross between F1progeny with it's recessive parent is called test cross.
Back cross:-The cross between F1progeny with any one of the parents is called back cross.
3.Law of independent assortment :-The law of independent assortment is a principle of inheritance that each heritable allele is inherited independently of one another.
4.complete linkage:-The genes are completely linked inherited in a set and no recombination is there.
The Genes are usually located very near to each other.
Incomplete linkage :-The Gene are not completely linked and recombination may occur. The genes may be a little far from each other.
5 .crossing over:-An exchange of homologous segments between the non sister chromatids. It occurs during pachytene of meosis-1 recombination occur during crossing over.
Unit 3 Db43
ReplyDelete1.monohybrid cross and di hybrid cross?
Monohybrid:cross made between two individuals differ in one character
Dihybrid:cross made between two individuals differ in two characters
2.what is Gene?
It's unit heritance contain information to express character
3.dominent and Recessive?
Dominent:where character expressed both in homozogous and in heterozogous condition
Tall-dwarf. Height
Round- wrinkle . Shape
4.what is pheno type and genotype?
Phenotype:physical or external morphological appears of an individual
Genotype:gentic make up an individual
5.short note on GJ Mendal?
He is called the father genectis he is a monk he a botanist he frist person to absorb or study the gentic character of aplant pisum sativm
DEAR DB- 43,
DeleteFIRST WRITE YOUR NAME AND WRITE PROPERLY
FIRST LETTER CAPITAL LETTER,
EXPLAIN THE CONTRIBUTION OF MENDAL
UNIT-1
ReplyDeletePlasmids
A genetic structure in a cell that can replicate independently of the chrosomes typically a small circular DNA strands in the cytoplasm of the bacterium or protozoan.
Mesosomes
An organelle of bacteria that appears as an invagination of plasma membrane and function either in DNA replication and cell division or excretion of enzymes.
Functions of cell walls
#It's flexible,but provide strength to cells against physical damage.
#it also gives the cell it's shape &allows the organism to maintain certain shape.
#it also provide protection from pathogens, such as bacteria that are trying to invade the cell.
Suicidal bags
Lysozymes are called as suicidal bags.They are filled with digestive enzymes.These enzymes also digest any kind of worn out cell organelles or foreign materials or viruses that enter the cell.
Satellite chromosomes
Chromosomes containing satellites are called satellite chromosomes.The satellite at metaphase appears to be attached to the rest of the body of chromosomes by a thread of chromatin.
UNIT-2
Nucleosome model
It is a bead like structure.A nucleosome is a basic unit of DNA packaging in eukaryotes, consisting of a segment of DNA wound in sequence around eight histone protein cores.This structure is often compared to thread wrapped around a pool.
Translation
Ribosomes in cytoplasm or endoplasmic reticulam synthesize proteins after the process of transcription of DNA to RNA in cells nucleus.In translation meninges DNA is decoded in ribosomes to produce a specific amino acids chain,or polypeptide chain.
Nucleotides
It consists of sugar molecule attached to a nitrogen base &a phosphate group.
Nucleoside
It consists of a sugar molecule attached to a nitrogen base.
Watson and Crick model.
They explained the structure of the DNA for which they have received Nobel prize.Deoxyrobonucleic acidis double stranded,helical molecule.It consists of two sugar-phosphate backbones on outside,held together by hydrogen bonds b/w pairs of nitrogenous bases on inside.
Semi- conservative replication
The progressive separation of the parental strands, each strand act as a template strand for the synthesis of a new complementary strand.As a result two DNA molecules are produced.In each molecule one strand is old& another one is new.
UNIT-I
ReplyDelete1. PLASMIDS_
Ans: Plasmid is a genetic structure in a cell that can replicate independently of the chromosome, typically a small circular DNA stand in cytoplasm of bacteria.It is used in the laboratory for manipulation of genes.
2. MESOSOMES_
Ans: Mesosomes are the folded invagination in the plasma membrane of bacteria. That are produced by chemical fixation h
3. CELL THEORY_
Ans: It was proposed by the “Schilden and Schwann”. All living organisms are composed of cells. Cells are basic unit of structure and functional unit of all living organisms. All cells are produced from the pre-existing cells.
4. SEMI-AUTONOMOUS CELL ORGANELLES_
Ans: Mitochondria is considered as the autonomous cell organelle due to the following counts. Mitochondria have their own DNA which can replicate independently. The mitochondrial DNA produces its own mRNA,tRNA and r RNA.The organelles have own ribosomes called mitoribosomes.
5. SUISIDAL BAGS_
Ans:LYSOSOMES are considered as suicidal bags because it has some hydrolytic(or)digestive enzymes which helps killing unnecessary components like virus/Bactria from cell. And while doing so it also damage it self .which leads to suicide
SUBMITTED BY
N.VISHAL SINGH.
DB-45(162445)
UNIT-3
ReplyDeleteCoupling & repulsion theory
The dominant alleles in one chromosome & recessive allele in another chromosome.
Both the dominant & recessive allele present in single chromosome
Test cross
The cross b/w F1 hybrid with it's recessive parent is called test cross.
Back cross
If a cross is made b/w F1 hybrid and with any one of it's parent.
Linkage
It is the presence of two or more genes on the chromosomes.As a result the genes inherited together more oftenly.
Incomplete dominance
It is the condition when one allele of a gene is not completely dominant over the other allele in the F1 generation.
UNIT-4
Plant breeding
It is a science based on principles of genetics & cytogenetics.If aims of improving the genetic make up of the crop plants.
Improve yield, quality, disease resistance, drought & important characteristics of crop plants.
Acclimatization
It is a process in which an individual organism adjust to a change in it's environment allowing it to maintain performance accross a range of environmental conditions.
Mass selection
When a large number of plants of similar phenotype are selected and their seeds are mixed together to constitue a new variety is called mass selection.
Pureline selection
Large number of plants are selected from a population of self pollinated crop,harvested individually & their individual progenies are evaluated&the best progenies are released as a pure line variety.
Clonal selection
The procedure of selection used for asexual crops is known as clonal selection.since the selected plants are used to produce new clones.
Inbreeding
It is a technique used in selective breeding.In plant breeding,in breed lines are used as stocks for the creation of hybrid lines to make use of the effects of the heterosis.In breeding plants also occurs naturally in the form of self pollination.
Emasculation
Removal of stamens or anthers or killing the pollen of flower without the female reproductive organ is known as emasculation.this process is done inin breeding to prevent self pollination.
UNIT-5
Molecular breeding
Use of genetic manipulation performed at DNA molecular levels to improve charecters of plants and animals.Its main objective is to develop plant varieties with desired traits.
RFLP
Restriction fragment length polymorphism.
RAPD
Random amplified polymorphic DNA.
Somaclonal variations
It is the term used to describe the variation seen in plants that have been produced by plants tissue culture.Chromosomal rearrangement are important source of this variation.
Mutagen
Physical or chemical agents which greatly enhance the mutation.
Spontaneous mutation
It arises spontaneously from natural changes in DNA structure or from error in replication.
Induced mutation
The changes caused by radiation of environmental chemicals are called as induced mutation.
A number of environmental agents are capable of damaging DNA including certain chemicals & radiations.
Submitted by G.Usha sri
Semester - V
ReplyDeleteBotany Paper - V
Title:Cell Biology,Genetics and Plant Breeding
Short Question and Answers for Semester End Exam
Unit - I - Cell Biology
1.What are the differences between Prokaryotic Cell and Eukaryotic Cell?
Ans). Prokaryotic Cell:
i.Nucleus is undefined and the nuclear material is present all over the cell.
ii.Single circular chromosome present.
iii.Plasmid is present which contains extra chromosomal genes which is used in R-DNA technology.
iv.Membrane bound organelles are absent.
v.Genetic material lacks histone proteins.
Eukaryotic Cell:
i.Nucleus is well defined and the nuclear material is bound by a nuclear membrane.
ii.Chromosomal number varies and they are of linear type.
iii.Plasmid is absent.
iv.Membrane bound organelles like mitochondria, chloroplast and etc are present.
v.Genetic material is associated with histone proteins.
2.What are Mesosomes?Mention it's role?
Ans).Mesosomes are the infoldings of the plasma membrane in a prokaryotic cell into the cytoplasm.
Mesosomes main function is respiration in prokaryotic cells.It also helps in the binary fisson and due to the more surface area present near it, many metabolic processes like enzymatic reactions undergo here.
3.What is a Plasmid? Mention it's role in R-DNA technology.
Ans). Plasmid is the extra chromosomal DNA present in a prokaryotic cell which can replicate independently.They are small circular double stranded DNA molecules in bacteria.
The sexual reproduction in bacteria i.e., Conjugation takes place by the transfer of plasmid from a donor cell having a plasmid to a recipient cell lacking a plasmid.
Plasmids play a major role in genetic recombinations in R-DNA technology which are of great use in science, agriculture,medicine and genetics.The desired genes are isolated from the organisms and by the help of vectors(plasmids) genetic recombinations are done in laboratory.
4.Distinguish between Euchromatin and Heterochromatin.
Ans). Euchromatin: The portion in the chromosome which takes less stain and active genes are present and they take part in transcription due to their loose packing.
Heterochromatin:The portion in the chromosome which takes up staining darkly and inactive genes are present.This is due to methylation of the chromatin material and high coiling.
5.What are semi-autonomous cell organelles?Why are they called so?
Ans).The mitochondria and chloroplast are known as the semi-autonomous cell organelles in a plant cell.
They are called as semi-autonomous cell organelles due to their ability to undergo autocatalysis and heterocatalysis.
Autocatalysis is the ability to replicate their own genetic material and heterocatalysis is the synthesis of proteins by transcription and translation
Submitted by : P.SANDHYA DB-1
UNIT-II
ReplyDelete6. NUCLEOSIDE AND NUCLEOTIDE_
Ans: Nucleoside consist of sugar molecule attached to the nitrogen base. Chemically it composed of Nitrogen bases and phosphates. Nucleotide it consists of sugar molecule attached to the nitrogen base and phosphate group. Chemically it composed of sugar molecule and nitrogen bases and phosphates.
7. DIFFERENCES OF DNA AND RNA_
Ans:DNA- It is a double standard molecule acting as universal genetic material. DNA contains deoxy ribose sugar molecule in its structure. It undergoes Autocatalysis and Heterocatalysis. It contains Thymine as one of the nitrogen base.
RNA-It is a single standard molecule which act as a genetic material in the absence of DNA molecule. It contains ribose sugar in its structure. It undergo translation to synthesis protein as a result of transcription by DNA. It contains Uracil instead of Thymine as a nitrogen base.
8. SEMI CONSERVATIVE METHOD OF REPLICATION_
Ans: The progressive separation of the two parental strands of each strand act as a template strand for the synthesis of new complementary strand. As a result 2 DNA molecules are produced in each molecule one strand is old and another is new strand.
9. WATSON AND CRICK_
Ans: Watson and crick proposed the Double helical structure of DNA. For which they got Noble prize in 1962.
10. NUCLEOSOME MODEL_
Ans:In eukaryotic nucleus the chromosomes are made up of DNA and the basic protein is called Histones. The chromosomes are in the form of chromatin material and it appears in the form of bead like structure called “Nucleosome”.
SUBMITTED BY
N.VISHAL SINGH.
DB-45(162445)
DEAR VISHAL,
DeleteWHY LOT OF SPACE BETWEEN 7 AND 8 QUESTIONS
WRITE COMPLETE FORM OF QUESTION
Unit - II - Genetic Material
ReplyDelete1. Define Nucleoside and Nucleotide.
Ans).Nucleoside:It consists of a sugar molecule attached to a nitogen base.
Nucleotide:It consists of a sugar molecule attached to a nitrogen base and a phosphate group.
2.Give any four differences between DNA and RNA.
Ans). DNA:
i.It is a double stranded molecule acting as univeral genetic material.
ii.DNA contains deoxy ribose sugar molecule in it's structure.
iii.Udergoes autocatalysis and heterocatalysis.
iv.Contains Thymine as one of the nitogen base.
RNA:
i.It is a single stranded molecule which act as a genetic material in the absence of DNA molecule.
ii.RNA contains ribose sugar in it's structure.
iii.Undergoes translation to synthesise protein as a result of transcription by DNA.
iv.Contains Uracil instead of Thymine as nitrogen base.
3.Give details about Watson and Crick.
Ans). Watson and Crick proposed the double helical structure of DNA molecule for which they received a Noble Prize in 1962 under Medicine.
4.Semi-conservative mode of DNA replication?
Ans).Semi-conservative mode of DNA replication was proposed by Watson and Crick in 1953.
They stated that each starnd in the parent DNA act as a template strand and the daughter strands are newly synthesised.The new daughter DNA contain one parental DNA strand and one newly synthesised strand.
5.Give the types of RNA and their functions.
Ans).There are three types of RNA.They are i.m-RNA-It is called messenger-RNA. It is transcribed from the DNA and carries the information for the protein synthesis.
ii.t-RNA-It is called transfer-RNA. It has stem loop structure. It carries amino acids to the site of protein synthesis and has anti-codon site which would be complementary to the mRNA sequence.
iii.r-RNA- It is called ribosomal-RNA. It is the site for the synthesis of proteins. It will help in attachment of the mRNA with the ribosomes.
Submitted by : P.SANDHYA DB-1
Unit-3:MENDLIAN INHERITANCE :
ReplyDelete1.Define test cross & back cross ?
.Test cross:The cross between F1 hybrid with its recessive parent .
.Back cross :If a cross is made between F1 hybrid with any one of its parent.
2.Define law of independent assortment?
. The law of independent assortment is a principle of inheritance that each heritable allele is inherited independently of one another.
3.Define law of dominance?
. The law of dominance "when two alleles of an inherited pair is heterozygous,then the allele that is expressed is dominant whereas the allele that is not expressed is recessive".
4.Define linkage and crossing over ?
.Linkage:The tendency of gene to remain together in the same chromosome .
.crossing over :An exchange of homologous segments between the non-sister chromatin .It occurs during pachytene surface of prophase-1 of meiosis-1 .Recombination of characters occur during crossing over.
5.Define coupling and repulsion theory?
. "Watson and pullet" in 1906 they discovered the phenomenon of linkage and crossing over by using "lathyrus" for their experiments .They observed coupling and repulsion process due which they proposed a theory called coupling and repulsion theory.
Coupling- If two alleles from the same parent then they enter into the same gamets and they transmit together these is called coupling.
Repulsion- when the same alleles come from the different parents then they will enter into different camera at the time of gametogenesis.
Submitted by : P.SANDHYA DB-1
Unit -4 PLANT BREEDING :
ReplyDelete1.Define plant breeding and mention two objectives?
.The phenomenon of development of new varieties of plants possessing desirable characters from the already existing varieties .
Objectives:
1.To obtain high yielding variety .
2.To improve disease,drought resistance.
2.Define acclimitization?
.Adjustment of introduced plants in new locality a changed climatic condition.such plants are disease resistance due to change in environment but chances to adultrent seeds.
Eg:Parthenon Hysterophorous
Argentina Mexicana
3.Define hybridization ?
.The mating or crossing of two plants or lines of dissimilar genotype is called hybridization .
Objectives:
1.To create genetic variation.
2.segregation and recombination produce many new gene combination.
4.Define pure line selection ?
.It can be defined as the process of isolating a desirable homozygous individual from the mixed population and multiplying the same without contamination to release as a new variety.
5.Define clonal selection ?
.A variety that is propagated vegetative from a single plant is clone of a single plant obtained by sexual reproduction or all vegetative progenies of a single plant is called a clone.
Submitted by :P.SANDHYA DB-1
Unit -5 BREEDING, CROP IMPROVMENT & BIOTECHNOLOGY:
ReplyDelete1.Define mutagen ?write any two types of agents ?
.The physical or chemical agents which greatly enhance the mutation is called mutagen .
Physical mutagen- uv radiation
Chemical mutagen -N- Nitroso N-methyl urea.
2.Define somaclonal variation ?
.The genetic variations found in the invitro cultured cells are collectively referred as somaclonal variation .
3.Define chromosomal theory?
.These theory was proposed by Morgan. According to him genes are present in the pairs of chromosomes and the chromosomal substances binds these linked genes together during the process of inheritance.The degree of linkage is determined by distance of the gene,if the genes are closer the linkage is very strong.
4.Expand RFLP and mention objectives?
.RFLP-Restriction frangemt length polymorphism.
Objectives:
1.It is extensively used in genome analysis.
2.The variation is the restriction DNA fragment lengths between individuals of a species.
5.Define inbreeding?
. The Mating of individuals or organisms that are closely related through common ancestry .
Submitted by :P.SANDHYA DB-1
UNIT-III
ReplyDelete11. MONO HYBRIS CROSS_
Ans: If a cross is made between two individuals differ in one character. This type of crossing s called mono hybrid cross.
12. TEST CROSS AND BACK CROSS_
Ans: TEST CROSS: The cross is made between the F1-generation hybrid with its recessive parent is called Test cross.
BACK CROSS: If a cross is made between the F1 hybrid with its any one of its parent. This type if crossing is called back cross.
13. LAW OF DOMINANCE_
Ans: Mendel’s law of dominance states that when two alleles of an inherited pair is heterozygous, then that allele expression is dominant whereas the allele that is not expressed that is recessive. The expression of the allele supressing the recessive allele is called as law of dominance.
14. DI HYBRID CROSS_
Ans: If a cross is made between two individuals differ in two contrasting characters. This type of crossing is called Dihybrid cross.
15. GENE, ALLELE, HOMOZYGOUS AND HETEROZYGOUS_
Ans: GENE: It is the unit of inheritance and it contains the information requires to express the character (A few nucleotide sequences of DNA).
SUBMITTED BY
N.VISHAL SINGH.
DB-45(162445)
UNIT-IV.
ReplyDelete16. PLANT BREEDING_
Ans: The phenomenon of development of new varieties of plants possessing desirable characters from the already existing varieties is called plant breeding.
Its objectives-
To obtain high yielding varieties.
To improve the quality of size and shape, colour, taste and durability of
Product.
To improve disease and drought resistance.
17. EMASULATION_
Ans: In the process of hybridisation technique the removal of anther (male sex organs) from the flower without disturb the female part. This process is called Emasculation.
18. ACCLIMATIZATION.
Ans: Adjustment of introduced plant in a new locality a changed climatic conditions. Such plants are resistance due to change environment but chance of adultrence. This is called acclimatization.
19. MASS SELECTION.
Ans: Number of phenotypically superior plants from field population harvesting and produce together for further year’s crop and repeating process until the desired characters are achieved. This selection is called mass selection.
20. HYBRIDISATION.
Ans: The mating or crossing of two plants or lines having dissimilar genotypes in known as hybridisation.
Objectives are_ To create genetic variation. And segregation and recombination produce many new gene recombinations.
SUBMITTED BY
N.VISHAL SINGH.
DB-45(162445)
UNTI-V
ReplyDelete21. DNA MARKERS.
Ans: It is a small segment of known DNA use in molecular biology and biotechnology to identify the sequence of genome in a tool of unknown DNA.
22. RFLP.
Ans: Restriction fragment length polymorphism.
Its objectives_ Allow the transfer of novel genes from related wild species. Established genetic relationship between sexually incompatible crop plants.
23. RAPD.
Ans: Random amplified polymorphic DNA.
Its objectives_ these markers are employed in the construction of genetic maps.
It is used to distinguish between varieties based on DNA sequences
24. MUTAGENS.
Ans: Agents which causing mutation in organisms are called mutations. There are different types of mutagens namely physical mutagens, chemical mutagens and biological mutagens.
25. TYPES OF CHROMOSOMAL MUTATIONS.
Ans: Deletion: Removal of small part
Inversion: Reattachment of same chromosome.
Translocation: Repetion of same gene sequences.
Non disjunction: transfer of a part of chromosome to another
Duplication: failure of chromosomes to separate during meiosis.
SUBMITTED BY
N.VISHAL SINGH.
DB-45(162445)
N. Prathyusha.
ReplyDeleteDB-27.
Unit-4 plant breeding.
1.Emasculation:-Emasculation means removal of stamens from the selected female flower is called emasculation .
It is done to prevent self pollination. This can be done by many methods.
Bagging :-After emasculation the female flower are covered with the help of polythene bag. This prevents unnecessary cross-pollination.
2.Acclimatization:-The newly introduced varieties has to adapt or or adjusted itself to the changed climatic conditions. This adjustment is called acclimatization.
3.Hybridization:-The mating or crossing of two plants or lines of dissimilar genotype is known as hybridization.
Objectives :-
To create genetic variation segregation and recombination produce many new gene combinations.
4.Plant breeding :-plant breeding is the process by which humans change the characteristics of plants over time to make then better crops and more nourishing food.in it's most simple form, breeding consists of selecting the best plants, in a given field, growing them to full seed and then using that seed to grow future generations.
Objectives :-
1.High yielding.
2.Disease resistant.
5.1.Introduction:-Introduction is the earliast of the methods followed in plant breeding. Established plants of one area are taken to the newer area far the use of mankind.
Merits:*It is very quick and economical method of crop improvement.
*It may provide an entirely a new group species. Maize, potato, tomato, are the best examples for introduction.
N. Prathyusha.
ReplyDeleteDB-27.
Unit-5 Breeding, crop improvement and biotechnology .
1.Spontaneous mutations :-If change occurs naturally in the DNA structure.
Induced mutations :-Change is caused by mutagens.
2.chromosomal mutations :-
*Deletion.
*Inversion.
*Translocation.
*Non disjunction.
*Duplication.
3.Mutagen:-Any agent that cause change.
Types of mutagebs:
*Physucal.
*Radiation and heat.
*Chemical.
*Ethyl methane sulphonate.
4.RFLP:-Restriction fragment length polymorphism.
Objectives :
1.Allow the transfer of novel genes from relatedvwild species.
2.Establish genetic relationship between sexually incompatible crop plant.
5.RAPD:-Rapid amplified polymorphic DNA.
1.RAPD markers are employed in the construction of genetic maps.
2.RAPD is used to distinguish between variety is based on difference in DNA sequence.
Submitted by :N. Prathyusha, DB -27...
UNIT-1
ReplyDeletePlasmids
A genetic structure in a cell that can replicate independently of the chrosomes typically a small circular DNA strands in the cytoplasm of the bacterium or protozoan.
Mesosomes
An organelle of bacteria that appears as an invagination of plasma membrane and function either in DNA replication and cell division or excretion of enzymes.
Functions of cell walls
#It's flexible,but provide strength to cells against physical damage.
#it also gives the cell it's shape &allows the organism to maintain certain shape.
#it also provide protection from pathogens, such as bacteria that are trying to invade the cell.
Suicidal bags
Lysozymes are called as suicidal bags.They are filled with digestive enzymes.These enzymes also digest any kind of worn out cell organelles or foreign materials or viruses that enter the cell.
Satellite chromosomes
Chromosomes containing satellites are called satellite chromosomes.The satellite at metaphase appears to be attached to the rest of the body of chromosomes by a thread of chromatin.
UNIT-2
Nucleosome model
It is a bead like structure.A nucleosome is a basic unit of DNA packaging in eukaryotes, consisting of a segment of DNA wound in sequence around eight histone protein cores.This structure is often compared to thread wrapped around a pool.
Translation
Ribosomes in cytoplasm or endoplasmic reticulam synthesize proteins after the process of transcription of DNA to RNA in cells nucleus.In translation meninges DNA is decoded in ribosomes to produce a specific amino acids chain,or polypeptide chain.
Nucleotides
It consists of sugar molecule attached to a nitrogen base &a phosphate group.
Nucleoside
It consists of a sugar molecule attached to a nitrogen base.
Watson and Crick model.
They explained the structure of the DNA for which they have received Nobel prize.Deoxyrobonucleic acidis double stranded,helical molecule.It consists of two sugar-phosphate backbones on outside,held together by hydrogen bonds b/w pairs of nitrogenous bases on inside.
Semi- conservative replication
The progressive separation of the parental strands, each strand act as a template strand for the synthesis of a new complementary strand.As a result two DNA molecules are produced.In each molecule one strand is old& another one is new.
UNIT-3
Coupling & repulsion theory
The dominant alleles in one chromosome & recessive allele in another chromosome.
Both the dominant & recessive allele present in single chromosome
Test cross
The cross b/w F1 hybrid with it's recessive parent is called test cross.
Back cross
If a cross is made b/w F1 hybrid and with any one of it's parent.
Linkage
It is the presence of two or more genes on the chromosomes.As a result the genes inherited together more oftenly.
Incomplete dominance
It is the condition when one allele of a gene is not completely dominant over the other allele in the F1 generation.
Submitted by K.sharanya Devi
DB-29
UNIT-4
ReplyDeletePlant breeding
It is a science based on principles of genetics & cytogenetics.If aims of improving the genetic make up of the crop plants.
Improve yield, quality, disease resistance, drought & important characteristics of crop plants.
Acclimatization
It is a process in which an individual organism adjust to a change in it's environment allowing it to maintain performance accross a range of environmental conditions.
Mass selection
When a large number of plants of similar phenotype are selected and their seeds are mixed together to constitue a new variety is called mass selection.
Pureline selection
Large number of plants are selected from a population of self pollinated crop,harvested individually & their individual progenies are evaluated&the best progenies are released as a pure line variety.
Clonal selection
The procedure of selection used for asexual crops is known as clonal selection.since the selected plants are used to produce new clones.
Inbreeding
It is a technique used in selective breeding.In plant breeding,in breed lines are used as stocks for the creation of hybrid lines to make use of the effects of the heterosis.In breeding plants also occurs naturally in the form of self pollination.
Emasculation
Removal of stamens or anthers or killing the pollen of flower without the female reproductive organ is known as emasculation.this process is done inin breeding to prevent self pollination.
UNIT-5
Molecular breeding
Use of genetic manipulation performed at DNA molecular levels to improve charecters of plants and animals.Its main objective is to develop plant varieties with desired traits.
RFLP
Restriction fragment length polymorphism.
RAPD
Random amplified polymorphic DNA.
Somaclonal variations
It is the term used to describe the variation seen in plants that have been produced by plants tissue culture.Chromosomal rearrangement are important source of this variation.
Mutagen
Physical or chemical agents which greatly enhance the mutation.
Spontaneous mutation
It arises spontaneously from natural changes in DNA structure or from error in replication.
Induced mutation
The changes caused by radiation of environmental chemicals are called as induced mutation.
A number of environmental agents are capable of damaging DNA including certain chemicals & radiations.
Submitted by K.sharanya Devi
DB-29
Unit:4. Db43
ReplyDelete1.what is plant breeding and objectives?
The branch of botany that daeals with the improvement of plants and their production
Objectives:obtain high yeild
Improve quality size shape colour
Improve diease resistant drought
2.emasulation ?
Removal of male sex organs selected plant without causing any damage male sex organs is called emasulation
3.hgbridization and types?
Mating of two plants of disimdissargenotypeis known as hybrization
Types
Intera varetial
Inter varetial
Inter spfic
Inter generic hybrization
4.what is mass selection?
Selection of phenotpically superior plants for production of new high quality plants
5.what is pure line selection and clonal selection?
Pure line selection:process of isolation of desirable homozogous indivuals from mixed without contamination of gamets and new species are formed
Clonal selection:propagation of plants from a single plant is called clone through asexual reproduction the process is called clonal selection
Unit:2. Db43
ReplyDelete1. Watson and crick ?
They were the frist perssons to Persons to propose the sturature of dna they said thatit has double strand structure and it xigram was given for that they were awarded Noble prize
2.semi conservative mode replication?
It process through which DNA replicates to from two strands one new strand another is world
3.nucelocite?
Copounds consting of nucleoside linked to a phosphate group
4.satellite chrmosomes?
It is present on top of chromosome like Beed like strcuture hence it is called satellite chromosome
5.type chrmosomesbased position of centromere?
Meta centric
Sub meta centric
Acro centric
Tell centric
Unit-1:CELL BIOLOGY
ReplyDelete1)What is Cell Theory and Mention it's Objectives?
Ans)Cell theory is one of the basic principals of biology . This theory says that new cells are formed from other existing cells. This theory was given by German scientists Schleiden, Schwann and Rudolf Virchow.
Objectives:
i)Living organisms composed of one (or) more cells.
ii)Cell is the most basic unit of life.
iii)All cells arise only from preexisting cells.
iv)Activity of an organism depend on the total activity of independent cells.
2)What is plasmid? Mention it's role?
Ans)Plasmids are extra chromosomal ,naked, small, circular, double stranded DNA molecules capable of self replicating and present in bacterial cells. Plasmids can integrate themselves with the main bacterial chromosome to form episomes. They are several types of plasmids F plasmid ,R plasmid etc..
3)What are mesosomes? Mention it's role?
Ans) Mesosomes are the finger like projections originated from plasma membrane into the cytoplasm of prokaryotic cells .The mesosomes are filled with respiratory enzymes.
The main function of mesosomes to perform respiration,it also increase the surface area of cell membrane, it also performs DNA replication.
4 ) Why mitochondria and chloroplast are called semiautonomous cell organelles?
Ans)Mitochondria and Chloroplast are called semi-autonomous cell organelles because they have their own genetic material and are capable of synthesising proteins required for their functioning.It also have ability to undergo auto catalysis and heterocatalysis.
5)Why Nucleus is called cell brain?
Ans) Replication occurs in the nucleus so it is called cell brain.
submitted by,
V.Dhanunjay chowdary
DB:03
Unit-2 GENETICS
ReplyDelete1)Semi conservative method of replication:.
Semiconservative replication produce two copies that each contained one of the original strand i.e,parental strand and one new strand i.e, daughter strand .semiconservative replication leaves the two original template DNA strands together in a double helix& produce a copy composed of two new strands containing of all the new DNA base pairs.
2)Hershey -chase experiment:
This experiment help it to confirm that DNA is a genetic material .They used T2 phage ,a bacteriophage. The phage infects a bacterium by attaching to it and injecting it's genetic material into it. They put labels on phage DNA with radioactive phosphorus.
They clearly showed that DNA of T2 phage is transmitted from one generation to next while proteins are not transmitted .Atleast in T2. phage ,DNA is genetic material.
3)Watson and Crick model:
They proposed double helix structure of DNA the also received a noble prize in 1962.
DNA is a double standard helical molecule. It consists of two sugar phosphate back bones on the outside held together by hydrogen bond between pairs of nitrogenous bases on inside.
4)Clover leaf model:
Holley proposed cloverleaf model in order to explain the structure of t-rna According to this model t-rna consists of 3 loop like structures.
The 3 loop are collected together with the help of an unequal stalk fight structure one side of a stalk is 3'end and another side is 5' end. The loop that is present opposite to a stalk called anticodon loop (or) Amino acid attachment site. In this loop only specific type of amino acid acid with specific triplet cordon attached during the process of protein synthesis. The remaining 2 lateral loops are enzyme recognising site and ribosomal recognising site .Transfer RNA identify and transport specific type of amino acid to the site of protein synthesis.
5)Nucleosome model:
The nucleosome is a bead like inside the nucleus if observed under the electron microscope.
The nucleosome consists of 8 basic proteins in the form of a core i.e, octamer.Around the core the DNA molecule wraps twice between two nucleosome a DNA is present that is called Linker DNA that is associated with a special type of protein H1 protein. Nucleosome consists the repeating uses of basic proteins and DNA in side the nucleus that is called chromatin material.
Submitted by,
V.Dhanunjay chowdary
DB:03
Unit-3:MENDLIAN INHERITANCE :
ReplyDelete1.Define test cross & back cross ?
.Test cross:The cross between F1 hybrid with its recessive parent .
.Back cross :If a cross is made between F1 hybrid with any one of its parent.
2.Define law of independent assortment?
. The law of independent assortment is a principle of inheritance that each heritable allele is inherited independently of one another.
3.Define law of dominance?
. The law of dominance "when two alleles of an inherited pair is heterozygous,then the allele that is expressed is dominant whereas the allele that is not expressed is recessive".
4.Define linkage and crossing over ?
.Linkage:The tendency of gene to remain together in the same chromosome .
.crossing over :An exchange of homologous segments between the non-sister chromatin .It occurs during pachytene surface of prophase-1 of meiosis-1 .Recombination of characters occur during crossing over.
5.Define coupling and repulsion theory?
. "Watson and pullet" in 1906 they discovered the phenomenon of linkage and crossing over by using "lathyrus" for their experiments .They observed coupling and repulsion process due which they proposed a theory called coupling and repulsion theory.
Coupling- If two alleles from the same parent then they enter into the same gamets and they transmit together these is called coupling.
Repulsion- when the same alleles come from the different parents then they will enter into different camera at the time of gametogenesis.
Submitted by,
V.Dhanunjay chowdary
DB:03
Unit:4 PLANT BREEDING
ReplyDelete1)What is Acclimatisation?
Ans)It is a phenomenon of which the individual plant species adapt to the surrounding environmental conditions .
2)What is plant breeding? Give any 2 objectives?
Ans)It is a science of changing the traits of plants in order to produce desired characteristics. It has been used to improve the quality of nutrition in products for humans and animals.
Objectives:
1) Higher yield
2) Disease and pest resistance.
3)Improved quality.
4) agronomic characters.
3)Define Mass line,Pure line, Clonal selection?
Ans) Mass line selection:
It can be defined as selection of a number of phenotypically superior seeds from the field population harvesting and bulking their produce together for sowing the next year's crop and process is repeated till desirable characters are achieved.
Pure line selection:
It can be defined as the process of isolating a desirable homozygous individuals from the mixed population and multiplying the same without contamination to release as a new variety.
Clonal selection:
A variety that is propagated vegetative from single parent is called clone. Selection of Desirable clones from the mixed population of vegetative propagated crops called clonal selection.
4)What is hybridisation?Any two objectives?
Ans) Mating (or) crossing of two plants of dissimilar genotype is called hybridisation.It does not change any genetic contents of organisms but it produces new combination of genes.
Objectives:
1)To create genetic variation,when two phenotypically different plants are brought together in F1.
2) Segregation and recombinations produce new gene combinations in F2 .
5)Define Emasculation and bagging?
Ans) Emasculation: Removal of stamens from the selected female flower is called emasculation. It is done to prevent self pollination. The emasculation can be done by many methods.
Bagging: After emasculation the female flowers are covered with the help of polythene bag . This prevents unnecessary cross pollination.
Submitted by,
V.Dhanunjay chowdary
DB:03
Name: Md babita
ReplyDeleteSection : DB 06
Unit 1
Plasmid:
It is a small circular double standard dna molecule that is distinct from cells it provides to bacterial cell with genetic advantages like antibiotic resistence
Mesosomes:
These are folded invaguinvagin in plma membrane of bacteria it helps to increase the surface area of cell membrane
Suicidal bags:
Lysosomes are called as suicidal bags they can digest any kind of Foreign material which entered into cell
Selective permeable membrane:
The membrane which allows selective molecules and ions to pass through it
Example: plasma membrane
Semi autonomous cell organell:
Mitochondria and chloroplast are called as semi autonomous cell organells because they have their own DNA which can replicate independently hence they are called semi autonomous cell organells
Unit 2
ReplyDeleteSemi coservative mode of replecation:
During DNA replication the double standard DNA seperasep and each strand is used as template for synthesis of new strand this results in the formation of two identical copies of original standard molecule
Nucleotide and Nucleoside :
Nucleoside: it consists of nitrogen base covalently attached to sugar but without phosphate group
Nucleotide: it consists of nitrogen base five carbon sugarand one morephosphate group
Watson and crick:
Watson and crick proposed double standard helix structure of DNA molecule for which they received Noble prize in 1962
Difference between DNA and Rna
DNA:
It is double standard molecule
It consists of deoxy ribose sugar molecules
It undergoes auto catalysis and hetericatalysis
It contains adinine,guanine,cytocine and thymine
RNA:
It is single standard molecule
It consists of ribose sugar
It undergoes translocation for synthesis of proteins
It contains adinine,guanine, cytocine and uracil
Traslocation:
The transfer of part of chromosome to different positions especially to homologous chromosome
Submitted by: Md babita
DB 06
Unit 03
ReplyDeleteMonohybrid cross:
The cross made between 2 individual differ in one character
Dihybrid cross:
The cross made between 2 individual differ in 2 contrasting characters
Test cross:
Cross made between F1 hybrid with one of it's recessive parents
Linkage:
It I'd presence of two or more genes on chromosome as a result the genes inherit together more ofenly
Crossing over:
An exchange of homologous segments between 2 no sister chromatids
It occurs during pachytene of meiosis 1
Submitted by : Md babita
DB 06
Unit 4
ReplyDeleteAcclimatization:
The newly introduced variety has to adopt to changed climatic condition the adjustment is called as acclimatization
Hybridization:
The crossing of two plants of dissimilar Geno type is known as hybridization
Objective:
To create genetic variations
Recombination produce many new Gene combination
Emasculation:
Removal of male sex organ in flower withour disturbing female part of flower
Bagging:
The flower is enclosed in suitable bag to prevent unnessasary pollination
Pureline selection:
It can be defined as process isolating desirable homizygous individubal from mixed population and multiplying same without contaminating the new variety
Plant breeding:
Development of new varieties of plants posses desirable characters from already existing varieties
Objectives:
To obtain high yeild variety
To improve quality and size of plant
Submitted by MD babita
DB 06
Submitted by:- Vikram Raja(DB-25)
ReplyDeleteUnit-1
1) Plasmids
Ans:-A plasmid is a small DNA molecule within a cell that is physically separated from a chromosomal DNA and can replicate independently. They are most commonly found as small circular, double-stranded DNA molecules in bacteria; however, plasmids are sometimes present in archaea and eukaryotic organisms.
2) Cell theory and its objectives
Ans:- Cell theory is one of the basic principals of biology. According to this theory new cells are formed from older existing cells. This theory was proposed by German scientists Schleiden, Schwann and Rudolf Virchow.\
3) Cell Brain
Ans:- Nucleus is other wise called as cell brain. Cell nuclei contain most of the cell's genetic material, organized as multiple long linear DNA molecules in a complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these chromosomes are the cell's nuclear genome and are structured in such a way to promote cell function. The nucleus maintains the integrity of genes and controls the activities of the cell by regulating gene expression—the nucleus is, therefore, the control center of the cell.
4) Satellite chromosome
Ans:-Satellite chromosomes are chromosomes that contain secondary constructs that serve as identifying markers. Besides the centromere, one or more secondary constrictions can also be observed in some chromosomes at metaphase. This is the case with the acrocentric chromosomes 13, 14, 15, 21 and 22; chromosomes which contain a segment that is separated from the main body of the chromosome by such a secondary constriction.[1][2] The secondary constrictions are always constant in their positions and hence can be used as markers to identify these particular chromosomes. The Y chromosome can also contain satellites, although these are thought to be translocations from autosomes.[3] Chromosomes containing satellites are called SAT Chromosomes. The term is due to Sergei Navashin, in 1912.
5) Suicidal bags
Ans:-Lysosomes are called ‘Suicidal Bags’ .They are present only in animal cells.These are the digestive bodies which contains digestive enzymes.They are called suicidal bags because when there is lack of oxygen and food they break to release the enzymes which digest the whole cell.
M.PRADEEP KUMAR DB:09
ReplyDeleteSEMISTER:5
BOTANY PAPER:5
TOPIC(CELL BIOLOGY,GENETICS AND PLANT BREEDING)
SHORT ANSWER QUESTIONS AND FOR SEMESTER END EXAMINATIONS.
UNIT-1
1.MESOSOMES:
An organelle of bateria that appears as an invagination of plasma membrane and funtion either in DNA replication and
cell division or excretion of enzyme.
2.What is plasmid? Mention it's role?
Ans)Plasmids are extra chromosomal ,naked, small, circular, double stranded DNA molecules capable of self replicating and present in bacterial cells. Plasmids can integrate themselves with the main bacterial chromosome to form episomes. They are several types of plasmids F plasmid ,R plasmid etc..
3.)What is Cell Theory and Mention it's Objectives?
Ans)Cell theory is one of the basic principals of biology . This theory says that new cells are formed from other existing cells. This theory was given by German scientists Schleiden, Schwann and Rudolf Virchow.
Objectives:
i)Living organisms composed of one (or) more cells.
ii)Cell is the most basic unit of life.
iii)All cells arise only from preexisting cells.
iv)Activity of an organism depend on the total activity of independent cells.
4.Why Nucleus is called cell brain?
Ans) Replication occurs in the nucleus so it is called cell brain.It also holds information needed to conduct most of the cells function.
5.Define fluid music model?
.In 1972,"Singer & Nicolson" proposed these highly advanced theory .
.The ends of the lipid molecules shows
hydrophilic and hydroponic head & tails rrespectively termed as " fluid mosaic mmodel".
UNIT-2
GENETIC MATERIAL
1.Semi conservative method of replication:.
Semiconservative replication produce two copies that each contained one of the original strand i.e,parental strand and one new strand i.e, daughter strand .semiconservative replication leaves the two original template DNA strands together in a double helix& produce a copy composed of two new strands containing of all the new DNA base pairs.
2.Nucleosome model:
The nucleosome is a bead like inside the nucleus if observed under the electron microscope.
The nucleosome consists of 8 basic proteins in the form of a core i.e, octamer.Around the core the DNA molecule wraps twice between two nucleosome a DNA is present that is called Linker DNA that is associated with a special type of protein H1 protein. Nucleosome consists the repeating uses of basic proteins and DNA in side the nucleus that is called chromatin material.
3.Watson and Crick model:
They proposed double helix structure of DNA the also received a noble prize in 1962.
DNA is a double standard helical molecule. It consists of two sugar phosphate back bones on the outside held together by hydrogen bond between pairs of nitrogenous bases on inside.
4.Define transduction and conjugation?
.Transduction:The process by which foreign DNA is introduced into a cell by a virus or viral vector.
.Conjugation:The transfer of genetic material between bacterial cell by direct cell-to-cell contact or by a bridge like connection between two cells.
5.Define lysis and bacteriophage?
.Lysis:The disintegration of cell by rupture of the cell wall or membrane.
.Bacteriophage:A virus that parasitizes
a bacterium by infecting it & reproducing inside it.
Unit-2
ReplyDelete6)Define Nucleotide and Nucleoside.
Ans:-A nucleoside consists of a nitrogenous base covalently attached to a sugar (ribose or deoxyribose) but without the phosphate group. A nucleotide consists of a nitrogenous base, a sugar (ribose or deoxyribose) and one to three phosphate groups.
7)Translation.
Ans:-In molecular biology and genetics, translation is the process in which ribosomes in the cytoplasm or ER synthesize proteins after the process of transcription of DNA to RNA in the cell's nucleus. The entire process is called gene expression.
8)Define Lysis and Bacteriophage.
Ans:- Breaking down of cell membrane with often by viral, enzymic, or osmotic mechanisms that compromise its integrity. A fluid containing the contents of lysed cells is called a lysate.
Bacteriophage:-A bacteriophage is a virus that infects and replicates within Bacteria and Archaea. Bacteriophages are composed of proteins that encapsulate a DNA or RNA genome, and may have relatively simple or elaborate structures.
9) Watson and crick
Ans:-"Molecular Structure of Nucleic Acids: A Structure for Deoxyribose Nucleic Acid" was the first article published to describe the discovery of the double helix structure of DNA, using X-ray diffraction and the mathematics of a helix transform. It was published by Francis Crick and James D. Watson in the scientific journal.
10)Semiconservation Model.
Ans:-Semiconservative replication describes the mechanism by which DNA is replicated in all known cells. It derives its name from the fact that this mechanism of transcription was one of three models originally proposed[1][2] for DNA replication:
Semiconservative replication would produce two copies that each contained one of the original strands and one new strand.
Conservative replication would leave the two original template DNA strands together in a double helix and would produce a copy composed of two new strands containing all of the new DNA base pairs.
Dispersive replication would produce two copies of the DNA, both containing distinct regions of DNA composed of either both original strands or both new strands.
Unit-3
ReplyDelete11)Law of Dominance
Ans:-Mendel's Law of Dominance states that recessive alleles will always be masked by dominant alleles. Therefore, a cross between a homozygous dominant and a homozygous recessive will always express the dominant phenotype, while still having a heterozygous genotype.
12)Test Cross & Back cross
Ans:-If a Cross made between F1 progeny with its recessive parent is called Test cross
If a cross is made between F1 progeny with anyone of its parents is known as Backcross
13)Law of independent Assortment
Ans:-The Law of Independent Assortment states that alleles for separate traits are passed independently of one another
14)Define Linkage and crossing over
Ans:-Linkage:The tendency of gene to remain together in the same chromosome .
.crossing over :An exchange of homologous segments between the non-sister chromatin .It occurs during pachytene surface of prophase-1 of meiosis-1 .Recombination of characters occur during crossing over.
15)Define nucleosome model?
.A bead like structure of the chromatin fibres each one composed of a octomer of histone and 146 base pair containing DNA molecules.
.The nucleosome model consists of 4 pairs of basic proteins H2A,H2B,H3B,H4.
Unit-4
ReplyDelete16)Define Plant breeding and mention any achievements
Ans:-The phenomenon of development of new varieties of plants possessing desirable characters from the already existing varieties. Its main objectives are to obtain high yielding variety, and to improve disease,drought resistance.
17) Acclimatisation
Ans:- The process in which a plant is introduced to a completely new enviornment other than its native habitat and making to adapt to such new enviornment is called Acclimatisation
18) Define Hybridisation and mention two objectives
Ans:-Crossing of two plants of dissimilar genotype.
Its main objectives are to create genetic variation.
Segregation and recombination produce many new gene.
19)Mutagen and Name any two types of agents
Ans:-Any agent that cause change to genes is called Mutagen
Types of mutagens:
Physical:
Radiation and heat
Chemical:
Ethyl methane sulfonate.
20) Somaclonal Variations
Ans:-Somaclonal variation is the variation seen in plants that have been produced by plant tissue culture. The term somaclonal variation is a phenomenon of broad taxonomic occurrence, reported for species of different ploidy levels, and for outcrossing and inbreeding, vegetatively and seed propagated, and cultivated and non-cultivated plants. Characters affected include both qualitative and quantitative traits.
Unit-5
ReplyDelete21)RFLP adnd its objectives
Ans:-restriction fragment length polymorphism (RFLP). Its objectives are Analysis of RFLP variation in genomes was a vital tool in genome mapping and genetic disease analysis.RFLP analysis was also the basis for early methods of genetic fingerprinting, useful in the identification of samples retrieved from crime scenes, in the determination of paternity, and in the characterization of genetic diversity or breeding patterns in animal populations.
22)RAPD and its objectives
Ans:-Random Amplification of Polymorphic DNA'.
Its objectives are The scientist performing RAPD creates several arbitrary, short primers (8–12 nucleotides), then proceeds with the PCR using a large template of genomic DNA, hoping that fragments will amplify. By resolving the resulting patterns, a semi-unique profile can be gleaned from an RAPD reaction.
23)DNA markers and role in plant breeding
Ans:-A genetic marker is a gene or DNA sequence with a known location on a chromosome that can be used to identify individuals or species. It can be described as a variation (which may arise due to mutation or alteration in the genomic loci) that can be observed. A genetic marker may be a short DNA sequence, such as a sequence surrounding a single base-pair change (single nucleotide polymorphism, SNP), or a long one, like minisatellites. Its objectives are Genetic markers can be used to study the relationship between an inherited disease and its genetic cause.Genetic markers have to be easily identifiable, associated with a specific locus, and highly polymorphic.
24) Define Inbreed lines
Ans:-"Inbred line" means a relatively stable and pure breeding strain resulting from at least four successive generations of controlled self-pollination or four successive generations of backcrossing in the case of male sterile lines.
25) Define Emasculation and BAgging
Ans:- Emasculation is the removal of sexual parts of Flower in order to get a desired sex of the flower that we need. For example if i need male flower i would remove stigma from the flower and same for female flower i would remove anthers from the flower.
Bagging:- This process where flower is needed to prevent from self pollination by covering the flower with covers like polythene bags These are used in Hybridization process.
PRADEEP KUMAR
ReplyDeleteDB-09
UNIT-3
MENDELIAN INHERITANCE
1.Define law of dominance?
. The law of dominance "when two alleles of an inherited pair is heterozygous,then the allele that is expressed is dominant whereas the allele that is not expressed is recessive".
2. Testcross and Backcross?
Test cross: The cross between F1 progeny and the recessive homozygous parent is called Test cross(Tt×tt)
In test cross both the progenies are obtained in F2 generation.
Back cross: if F1 hybrid is crossed with one of its parents is called back cross.(Tt×TT/tt).When F1 hybrid is back crossed with dominant phenotype no recessive individual are obtained in the progeny.
3.Define coupling and repulsion theory?
. "Watson and pullet" in 1906 they discovered the phenomenon of linkage and crossing over by using "lathyrus" for their experiments .They observed coupling and repulsion process due which they proposed a theory called coupling and repulsion theory.
Coupling- If two alleles from the same parent then they enter into the same gamets and they transmit together these is called coupling.
Repulsion- when the same alleles come from the different parents then they will enter into different camera at the time of gametogenesis.
4.Define law of independent assortment?
. The law of independent assortment is a principle of inheritance that each heritable allele is inherited independently of one another.
5.Define the second law of Mendelian Inheritance.
Ans).The second law of Mendelian Inheritance is The Law of Independant Assortment of Gametes which states that "When two or more characteristics are inherited, individual hereditary factors assort independently during gamete production, giving different traits an equal opportunity of occurring together."
UNIT-4
PLANT BREEDING
1.Define acclimitization?
.Adjustment of introduced plants in new locality a changed climatic condition.such plants are disease resistance due to change in environment but chances to adultrent seeds.
Eg:Parthenon Hysterophorous
Argentina Mexicana
2.Define clonal selection ?
.A variety that is propagated vegetative from a single plant is clone of a single plant obtained by sexual reproduction or all vegetative progenies of a single plant is called a clone.
3.What is Plant Breeding? Give any two objectives.
Ans). Plant breeding is the process by which humans change the characteristics of plants over time to make them better crops and more nourishing food. In its most simple form, breeding consists of selecting the best plants in a given field, growing them to full seed and then using that seed to grow further generations.
Objectives:The main objectives are
i.High Yielding
ii.Disease Resistance
4.Define hybridization ?
.The mating or crossing of two plants or lines of dissimilar genotype is called hybridization .
Objectives:
1.To create genetic variation.
2.segregation and recombination produce many new gene combination.
5.Define Mass line,Pure line, Clonal selection?
Ans) Mass line selection:
It can be defined as selection of a number of phenotypically superior seeds from the field population harvesting and bulking their produce together for sowing the next year's crop and process is repeated till desirable characters are achieved.
Pure line selection:
It can be defined as the process of isolating a desirable homozygous individuals from the mixed population and multiplying the same without contamination to release as a new variety.
Clonal selection:
A variety that is propagated vegetative from single parent is called clone. Selection of Desirable clones from the mixed population of vegetative propagated crops called clonal selection.
1.What are the differences between Prokaryotic Cell and Eukaryotic Cell?
ReplyDeleteAns). Prokaryotic Cell:
i.Nucleus is undefined and the nuclear material is present all over the cell.
ii.Single circular chromosome present.
iii.Plasmid is present which contains extra chromosomal genes which is used in R-DNA technology.
iv.Membrane bound organelles are absent.
v.Genetic material lacks histone proteins.
Eukaryotic Cell:
i.Nucleus is well defined and the nuclear material is bound by a nuclear membrane.
ii.Chromosomal number varies and they are of linear type.
iii.Plasmid is absent.
iv.Membrane bound organelles like mitochondria, chloroplast and etc are present.
v.Genetic material is associated with histone proteins.
2.What are Mesosomes?Mention it's role?
Ans).Mesosomes are the infoldings of the plasma membrane in a prokaryotic cell into the cytoplasm.
Mesosomes main function is respiration in prokaryotic cells.It also helps in the binary fisson and due to the more surface area present near it, many metabolic processes like enzymatic reactions undergo here.
3.What is a Plasmid? Mention it's role in R-DNA technology.
Ans). Plasmid is the extra chromosomal DNA present in a prokaryotic cell which can replicate independently.They are small circular double stranded DNA molecules in bacteria.
The sexual reproduction in bacteria i.e., Conjugation takes place by the transfer of plasmid from a donor cell having a plasmid to a recipient cell lacking a plasmid.
Plasmids play a major role in genetic recombinations in R-DNA technology which are of great use in science, agriculture,medicine and genetics.The desired genes are isolated from the organisms and by the help of vectors(plasmids) genetic recombinations are done in laboratory.
4.Distinguish between Euchromatin and Heterochromatin.
Ans). Euchromatin: The portion in the chromosome which takes less stain and active genes are present and they take part in transcription due to their loose packing.
Heterochromatin:The portion in the chromosome which takes up staining darkly and inactive genes are present.This is due to methylation of the chromatin material and high coiling.
5.What are semi-autonomous cell organelles?Why are they called so?
Ans).The mitochondria and chloroplast are known as the semi-autonomous cell organelles in a plant cell.
They are called as semi-autonomous cell organelles due to their ability to undergo autocatalysis and heterocatalysis.
Autocatalysis is the ability to replicate their own genetic material and heterocatalysis is the synthesis of proteins by transcription and translation.
1.What are the differences between Prokaryotic Cell and Eukaryotic Cell?
ReplyDeleteAns). Prokaryotic Cell:
i.Nucleus is undefined and the nuclear material is present all over the cell.
ii.Single circular chromosome present.
iii.Plasmid is present which contains extra chromosomal genes which is used in R-DNA technology.
iv.Membrane bound organelles are absent.
v.Genetic material lacks histone proteins.
Eukaryotic Cell:
i.Nucleus is well defined and the nuclear material is bound by a nuclear membrane.
ii.Chromosomal number varies and they are of linear type.
iii.Plasmid is absent.
iv.Membrane bound organelles like mitochondria, chloroplast and etc are present.
v.Genetic material is associated with histone proteins.
2.What are Mesosomes?Mention it's role?
Ans).Mesosomes are the infoldings of the plasma membrane in a prokaryotic cell into the cytoplasm.
Mesosomes main function is respiration in prokaryotic cells.It also helps in the binary fisson and due to the more surface area present near it, many metabolic processes like enzymatic reactions undergo here.
3.What is a Plasmid? Mention it's role in R-DNA technology.
Ans). Plasmid is the extra chromosomal DNA present in a prokaryotic cell which can replicate independently.They are small circular double stranded DNA molecules in bacteria.
The sexual reproduction in bacteria i.e., Conjugation takes place by the transfer of plasmid from a donor cell having a plasmid to a recipient cell lacking a plasmid.
Plasmids play a major role in genetic recombinations in R-DNA technology which are of great use in science, agriculture,medicine and genetics.The desired genes are isolated from the organisms and by the help of vectors(plasmids) genetic recombinations are done in laboratory.
4.Distinguish between Euchromatin and Heterochromatin.
Ans). Euchromatin: The portion in the chromosome which takes less stain and active genes are present and they take part in transcription due to their loose packing.
Heterochromatin:The portion in the chromosome which takes up staining darkly and inactive genes are present.This is due to methylation of the chromatin material and high coiling.
5.What are semi-autonomous cell organelles?Why are they called so?
Ans).The mitochondria and chloroplast are known as the semi-autonomous cell organelles in a plant cell.
They are called as semi-autonomous cell organelles due to their ability to undergo autocatalysis and heterocatalysis.
Autocatalysis is the ability to replicate their own genetic material and heterocatalysis is the synthesis of proteins by transcription and translation.
Unit-2: GENETICS:
ReplyDelete1.Define nucleosome model?
.A bead like structure of the chromatin fibres each one composed of a octomer of histone and 146 base pair containing DNA molecules.
.The nucleosome model consists of 4 pairs of basic proteins H2A,H2B,H3B,H4.
2.Define transduction and conjugation?
.Transduction:The process by which foreign DNA is introduced into a cell by a virus or viral vector.
.Conjugation:The transfer of genetic material between bacterial cell by direct cell-to-cell contact or by a bridge like connection between two cells.
3.Define translocation?
.The transfer of part of a chromosome to a different position especially,on nonhomologous chromosome.
4.Define lysis and bacteriophage?
.Lysis:The disintegration of cell by rupture of the cell wall or membrane.
.Bacteriophage:A virus that parasitizes
a bacterium by infecting it & reproducing inside it.
5.Define semi conservative model?
.The progressive separation of the two parental strands,each strand act as a template strand for the synthesis of new complementary strand.As a result two DNA molecules are produced. Each molecule one is old and anotherstrand is new strand.
Unit - 3
ReplyDeleteMonohybrid cross:
The cross is made b/w 2 induviduals differ in one character.
Dihybrid cross:
The cross is made b/w 2 induviduals differ in two contrasting character.
Test cross:
Cross made b/w F1 hybrid with its recessive parent.
Back cross:
If a cross is made b/w F1 hybrid with any one of its parents.
Linkage:
It is a presence of two or more genes on the chromosomes as a result the genes inherited together more offenly.
Euchromatin:
Light strain
Less condensed
G snd C are more rich.
Heterochromatin:
Dark strain
More condensed
A and T are more.
Crossing over:
An exchange of homologous segments b/w the non sister chromatids.
It occurs during pachytene of meosis- 1
Recombination occurs during crossing over.
UNIT-1:-Cell Biology
ReplyDelete1)Plasmids:
A genetic structure in a cell that can replicate independently of the chrosomes typically a small circular DNA strands in the cytoplasm of the bacterium or protozoan.
2)Mesosomes:-
An organelle of bacteria that appears as an invagination of plasma membrane and function either in DNA replication and cell division or excretion of enzymes.
3)Functions of cell walls:-
-It's flexible,but provide strength to cells against physical damage.
-it also gives the cell it's shape &allows the organism to maintain certain shape.
-it also provide protection from pathogens, such as bacteria that are trying to invade the cell.
4)Suicidal bags:-
Lysozymes are called as suicidal bags.They are filled with digestive enzymes.These enzymes also digest any kind of worn out cell organelles or foreign materials or viruses that enter the cell.
5)Satellite chromosomes:-
Chromosomes containing satellites are called satellite chromosomes.The satellite at metaphase appears to be attached to the rest of the body of chromosomes by a thread of chromatin.
UNIT-2:-Genetics
1)Nucleosome model:-
It is a bead like structure.A nucleosome is a basic unit of DNA packaging in eukaryotes, consisting of a segment of DNA wound in sequence around eight histone protein cores.This structure is often compared to thread wrapped around a pool.
2)Translation:-
Ribosomes in cytoplasm or endoplasmic reticulam synthesize proteins after the process of transcription of DNA to RNA in cells nucleus.In translation meninges DNA is decoded in ribosomes to produce a specific amino acids chain,or polypeptide chain.
3)Nucleotides:-
It consists of sugar molecule attached to a nitrogen base &a phosphate group.
Nucleoside:-
It consists of a sugar molecule attached to a nitrogen base.
4)Watson and Crick model:-
They explained the structure of the DNA for which they have received Nobel prize.Deoxyrobonucleic acidis double stranded,helical molecule.It consists of two sugar-phosphate backbones on outside,held together by hydrogen bonds b/w pairs of nitrogenous bases on inside.
5)Semi- conservative replication:-
The progressive separation of the parental strands, each strand act as a template strand for the synthesis of a new complementary strand.As a result two DNA molecules are produced.In each molecule one strand is old& another one is new.
Submitted by:
G.Cristy Samuel John
DB-30
M.PRADEEP KUMAR
ReplyDeleteDB-09
UNIT-5
BREDDING,CORP IMPROVMENT AND BIO-TECHNOLOGY
1.)DNA markers? And role in plant breeding?
Ans) It is a fragment of DNA that is associated with in the genome in order to trace genetic alternations especially in the branch of biotechnology and molecular biology.DNA markers are used to identify particular sequence of DNA in a pool of unknown DNA.
Ex:RFLP,RAPD.
2.RAPD:random amplified polymorphic dna
Objectives:
These markers are employed in the construction of genetic map.
Used to distinguish between variety based on difference in DNA sequence
3..Mass selection :
Number of phenotypically superior plants from field population harvesting and bulking produce together for next year's crop and repeating process till desired characters are achieved.
Pureline selection:
Process of isolating a desirable homozygous individual from mixed population and multiplying the same without contamination to release as a new variety.
Clonal selection:
A variety is propagated vegetative from a single plant called clone or single plant obtained by asexual reproduction.
4.Expand RFLP and mention it's objectives?
Ans).RFLP-Restriction Fragment Length Polymorphism
Objectives:
i.Allow the transfer of novel genes from related wild species.
ii.Establish genetic relationships between sexually incompatible crop plants.
5.Define Somaclonal Variations?
Ans).Somaclonal variation is the variation seen in plants that have been produced by plant tissue culture. Chromosomal rearrangements are an important source of this variation.
Objectives:
i.Somaclonal variation leads to the creation of additional genetic variability.
ii.The major likely benefit of somaclonal variation is plant improvement.
SUBMITTED BY:M.PRADEEP KUMAR
Unit - III - Mendelian Inheritance
ReplyDelete1. Define law of Dominance.
Ans).Mendel's law stating that when two alleles of an inherited pair is heterozygous, then, the allele that is expressed is dominant whereas the allele that is not expressed is recessive. The expression of the dominant allele suppressing the recessive allele is termed as Law of Dominance.
2.Define Test Cross and Back Cross.
Ans).Test Cross:The cross made between the F1 hybrid with it's recessive parent.It is done to know the homozygosity of the F1 hybrid.
Back Cross:The cross made between the F1 hybrid with any one of the parents.It is done in order to achieve offspring with a genetic identity which is closer to that of the parent.
3.Define Linkage and Crossing Over.
Ans).Linkage:It is the tendency of DNA sequences that are close together on a chromosome to be inherited together during the meiosis phase of sexual reproduction.
Crossing Over:It is the process where 2 homologous chromosome sister chromatids pair up with each other and exchange different segments of genetic material to form 2 recombinant chromosome sister chromatids.
4.Define the second law of Mendelian Inheritance.
Ans).The second law of Mendelian Inheritance is The Law of Independant Assortment of Gametes which states that "When two or more characteristics are inherited, individual hereditary factors assort independently during gamete production, giving different traits an equal opportunity of occurring together."
5.Define Complete Linkage and Incomplete Linkage.
Ans).Complete Linkage: It is defined as the state in which two loci are so close together that alleles of these loci are virtually never separated by crossing over. The closer the physical location of two genes on the DNA, the less likely they are to be separated by a crossing-over event.
Incomplete Linkage:When the genes were loosly linked on a chromosome and show higher percentage of recombination. In such condition non parental type of gametes are formed.
Incomplete linkage produces new combinations of the genes in the progeny due to the formation of chiasma or crossing over in between the linked genes present on homologous chromosomes.
Unit - IV - Plant Breeding
ReplyDelete1.What is Plant Breeding? Give any two objectives.
Ans). Plant breeding is the process by which humans change the characteristics of plants over time to make them better crops and more nourishing food. In its most simple form, breeding consists of selecting the best plants in a given field, growing them to full seed and then using that seed to grow further generations.
Objectives:The main objectives are
i.High Yielding
ii.Disease Resistance
Plant Breeding aims to improve the characteristics of plant so that they become more desirable agronomically and economically. Thus, the chief objective of plant breeding is to develop such improved varieties of crop plants that will be commercially successful.
2.Define Acclimatization.
Ans). Acclimatization is the phenomenom of an intoduced plant to adapt or adjust to the new environmental conditions.
3.Define hybridization ?
.The mating or crossing of two plants or lines of dissimilar genotype is called hybridization .
Objectives:
1.To create genetic variation.
2.segregation and recombination produce many new gene combination.
4.Define pure line selection ?
.It can be defined as the process of isolating a desirable homozygous individual from the mixed population and multiplying the same without contamination to release as a new variety.
5.Define clonal selection ?
.A variety that is propagated vegetative from a single plant is clone of a single plant obtained by sexual reproduction or all vegetative progenies of a single plant is called a clone.
Unit 05
ReplyDeleteMutagen:
The physical or chemical agents which greatly enhance the mutation is called mutagen
Example: u v radiations
N- nitroso N - methyl urea
Spontaneous mutations :
The change occur naturally in DNA structure is called spontaneous mutations
Induced mutations :
The change occur is caused by mutagen
Somaclonal variations:
The genetic variations found in the in vitri cultured cells are collectively called as simaclonal variations
RFLP:
Restriction fragment length polymorphism
RAPD:
Rapid amplifier polymorphic DNA
Inbreeding
The mating of individuals that are closely related through common ancestors is called in breeding
Submitted by: Md babita
DB 06
Unit -5
ReplyDeleteSpontaneous mutations:
If change occurs naturally in the DNA Structure.
Induced mutations:
Change is caused by mutagens.
Chromosomal mutations:
Deletion
Inversion
Translocation
Non disjunction
Duplication.
Mutagen:
Any agent that cause change
Types of mutagens:
Physical:
Radiation and heat
Chemical:
Ethyl methane sulfonate.
DNA markers:
It is a small segment of known DNA that is used in molecular biology to identify sequence of genome in a pool of unknown DNA.
RFLP:
Restriction fragment length polymerization.
RAPD:
Rapid amplify Polymorphic DNA.
20)Define spontaneous and induced mutations?
ReplyDeleteAns) Spontaneous mutation:If change caused by radiation in a DNA structure.
Induced mutation:Change caused by radiation or environmental mutagen
22)Define chromosomal theory?
Ans)These theory was proposed by Morgan. According to him genes are present in the pairs of chromosomes and the chromosomal substances binds these linked genes together during the process of inheritance.The degree of linkage is determined by distance of the gene,if the genes are closer the linkage is very strong
23.Define hybridization ?
Ans)The mating or crossing of two plants or lines of dissimilar genotype is called hybridization .
Objectives:
1.To create genetic variation.
2.segregation and recombination produce many new gene combination.
24)Hershey -chase experiment
Ans)This experiment help it to confirm that DNA is a genetic material .They used T2 phage ,a bacteriophage. The phage infects a bacterium by attaching to it and injecting it's genetic material into it. They put labels on phage DNA with radioactive phosphorus.
They clearly showed that DNA of T2 phage is transmitted from one generation to next while proteins are not transmitted .Atleast in T2. phage ,DNA is genetic material.
25)Watson and Crick model:
Ans)They proposed double helix structure of DNA the also received a noble prize in 1962.
DNA is a double standard helical molecule. It consists of two sugar phosphate back bones on the outside held together by hydrogen bond between pairs of nitrogenous bases on inside. S
Submitted by
K.phaneendra
DB: 52
Botany paper-5
ReplyDeleteSemester-5
Topics:Cell biology,Genetics and Plant breeding
Unit-1
1)What is plasmid? Mention it's role?
Ans)Plasmids are extrachromosomal,naked, small, circular, double stranded DNA molecules capable of self replicating and present in bacterial cells. Plasmids can integrate themselves with the main bacterial chromosome to form episomes. They are several types of plasmids F plasmid ,R plasmid etc.
2)What are mesosomes? Mention it's role?
Ans) Mesosomes are the finger like projections originated from plasma membrane into the cytoplasm of prokaryotic cells .The mesosomes are filled with respiratory enzymes.
3)Why mitochondria and chloroplast are called semiautonomous cell organelles?
Ans)Mitochondria and Chloroplast are called semi-autonomous cell organelles because they have their own genetic material and are capable of synthesising proteins required for their functioning.It also have ability to undergo auto catalysis and heterocatalysis.
4)Why Nucleus is called cell brain?
Ans) Replication occurs in the nucleus so it is called cell brain.It also holds information needed to conduct most of the cells function.
5)Define sui-cidal bags?
.Lysosomes are known as "sui-cidal bags of the cell".Lysosomes are single membrane move immatured/embryonic cells round shape.Lysosomes are primary and secondary.primary- filled with hydrolytic enzyme,actively involve in all functions.secondary-filled with undigested food material.
Submitted by:P.ManiKanta.
Regd no:DB-51.
P.HARIKA DB-22
ReplyDeleteSEMESTER-5
BOTANY PAPERP-5
TOPIC:CELL BIOLOGY,GENETICS AND PLANT BREEDING
SHORT QUESTIONS AND ANSWERS FOR SEMESTER AND EXAMINATION
UNIT-1
CELL BIOLOGY
1.What is mesosomes?
.The plasma membrane shows the finger like projections/folding called "mesosomes.
.mesosomes tends to increase the plasma membrane's surface and in turn also increases their enzymatic contents.
.It helps in the respiratory process .
2.why plasma membrane is called as selectively permeable membrane?
.The plasma membrane is a thin,elastic membrane around the cell.
.The plasma membrane and other intra-cellular membrane are selective in nature.such membrane allow only selected ions and some molecules to pass through them.
.The selective permeability of plasma membrane allows the cell to maintain constant internal environment .
3.Define sui-cidal bags?
.Lysosomes are known as "sui-cidal bags.
.Lysosomes are single membrane move immatured/embryonic cells round shape.
.Lysosomes are primary and secondary.
.primary- filled with hydrolytic enzyme,actively involve in all functions.
.secondary-filled with undigested food material .
4.NUCLEOSOME MODEL:
A nucleosome is a basic unit of DNA packaging in eukaryotes,consisting of a segment of DNA wound in sequence around eight histone protien cores. This structure often compared to thread wrapped around a pool.
5.CELL THEORY:
Living organisms are made up of cells.
Cells are basic structural and functional unit of all organisms.
Cells come from pre- existing cells.
UNIT-3:-Mendelian Inheritance
ReplyDelete1)Coupling phase:
The dominant alleles in one chromosome & recessive allele in another chromosome.
Repulsion phase:
Both the dominant & recessive allele present in single chromosome.
2)Test cross:-
The cross b/w F1 hybrid with it's recessive parent is called test cross.
3)Back cross:
If a cross is made b/w F1 hybrid and with any one of it's parent.
4)Linkage:
It is the presence of two or more genes on the chromosomes.As a result the genes inherited together more oftenly.
5)Incomplete dominance:
It is the condition when one allele of a gene is not completely dominant over the other allele in the F1 generation.
UNIT-4:-Plant Breeding
1)Plant breeding:
It is a science based on principles of genetics & cytogenetics.If aims of improving the genetic make up of the crop plants.
-Improve yield, quality, disease resistance, drought & important characteristics of crop plants.
2)Acclimatization:
It is a process in which an individual organism adjust to a change in it's environment allowing it to maintain performance accross a range of environmental conditions.
3)Mass selection:
When a large number of plants of similar phenotype are selected and their seeds are mixed together to constitue a new variety is called mass selection.
Pureline selection:
Large number of plants are selected from a population of self pollinated crop,harvested individually & their individual progenies are evaluated&the best progenies are released as a pure line variety.
Clonal selection:
The procedure of selection used for asexual crops is known as clonal selection.since the selected plants are used to produce new clones.
4)Inbreeding:
It is a technique used in selective breeding.In plant breeding,in breed lines are used as stocks for the creation of hybrid lines to make use of the effects of the heterosis.In breeding plants also occurs naturally in the form of self pollination.
5)Emasculation:
Removal of stamens or anthers or killing the pollen of flower without the female reproductive organ is known as emasculation.this process is done inin breeding to prevent self pollination.
UNIT-5:-Breeding,Crop improvement and Biotechnology
1)Molecular breeding:
Use of genetic manipulation performed at DNA molecular levels to improve charecters of plants and animals.Its main objective is to develop plant varieties with desired traits.
2)RFLP:
Restriction fragment length polymorphism.
RAPD:
Random amplified polymorphic DNA.
3)Somaclonal variations:
It is the term used to describe the variation seen in plants that have been produced by plants tissue culture.Chromosomal rearrangement are important source of this variation.
4)Mutagen:
Physical or chemical agents which greatly enhance the mutation.
5)Spontaneous mutation:
It arises spontaneously from natural changes in DNA structure or from error in replication.
Induced mutation:
The changes caused by radiation of environmental chemicals are called as induced mutation.
-A number of environmental agents are capable of damaging DNA including certain chemicals & radiations.
submitted by:
G.Christy Samuel John
DB-30
P.HARIKA
ReplyDeleteDB.22
BOTANY PAPER-5
UNIT-1
1.PLASMIDS:
A gentic structure in a cell that can replicate independently of the chromosome Typically small circular DNA strands in the cytoplasam of the bacterium.
2.MESOSOMES:
An organelle of bateria that appears as an invagination of plasma membrane and funtion either in DNA replication andcell division or excretion of enzyme.
3.SUICIDAL BAGS:
Lysosomes are called as suicidal bags. They are filled with digestive enzyme. These enzymes also digest any kind of worn out cell organelles or foreign materials bacteria or virus that enter the cell.
4.NUCLEOSOME MODEL:
A nucleosome is a basic unit of DNA packaging in eukaryotes,consisting of a segment of DNA wound in sequence around eight histone protien cores. This structure often compared to thread wrapped around a pool.
5.CELL THEORY:
Living organisms are made up of cells.
Cells are basic structural and functional unit of all organisms.
Cells come from pre- existing cells.
UNIT-2
ReplyDelete1)Watson and Crick model:
They proposed double helix structure of DNA the also received a noble prize in 1962.
DNA is a double standard helical molecule. It consists of two sugar phosphate back bones on the outside held together by hydrogen bond between pairs of nitrogenous bases on inside.
2)Clover leaf model:
Holley proposed cloverleaf model in order to explain the structure of t-rna According to this model t-rna consists of 3 loop like structures.
The 3 loop are collected together with the help of an unequal stalk fight structure one side of a stalk is 3'end and another side is 5' end. The loop that is present opposite to a stalk called anticodon loop (or) Amino acid attachment site. In this loop only specific type of amino acid acid with specific triplet cordon attached during the process of protein synthesis. The remaining 2 lateral loops are enzyme recognising site and ribosomal recognising site .Transfer RNA identify and transport specific type of amino acid to the site of protein synthesis.
3)Nucleosome model:
The nucleosome is a bead like inside the nucleus if observed under the electron microscope.
The nucleosome consists of 8 basic proteins in the form of a core i.e, octamer.Around the core the DNA molecule wraps twice between two nucleosome a DNA is present that is called Linker DNA that is associated with a special type of protein H1 protein. Nucleosome consists the repeating uses of basic proteins and DNA in side the nucleus that is called chromatin material.
4.Define transduction and conjugation?
.Transduction:The process by which foreign DNA is introduced into a cell by a virus or viral vector.
.Conjugation:The transfer of genetic material between bacterial cell by direct cell-to-cell contact or by a bridge like connection between two cells.
5.Define translocation?
.The transfer of part of a chromosome to a different position especially,on nonhomologous chromosome.
Unit-2:Geneics
ReplyDelete1)Define Watson and Crick model ?
A.watson and Crick proposed DNA double
helix Model(1953).It consists of two
Phosphate chains which act as backbones.The nitrogen base pairs are connected by Hydrogen bonds.Both the phosphate chains run opposite around the central axis.Watson and Crick are awarded with a nobel prize in the year (1962)for their discovery.
2)what is semi conservative method of
replication?
A.The progressive separation of two
parental strands,each strand act as
template strand for synthetis of new
Complementary strand .As a result two DNA Molecules are produced.each molecule has one old and new strands.
3)Define nucleosome model?
A) A bead like structure of the chromatin fibres each one composed of a octomer of histone and 146 base pair containing DNA molecules.The nucleosome model consists of 4 pairs of basic proteins H2A,H2B,H3B,H4.
4)Define Nucleoside and Nucleotide.
Ans).Nucleoside:It consists of a sugar molecule attached to a nitogen base.
Nucleotide:It consists of a sugar molecule attached to a nitrogen base and a phosphate group.
5)Define translocation?
A)The transfer of part of a chromosome to a different position especially,on nonhomologous chromosome is called translocation.
Submitted by:
P.Manikanta,
DB-51.
unit-3
ReplyDelete1.Define test cross & back cross ?
.Test cross:The cross between F1 hybrid with its recessive parent .
.Back cross :If a cross is made between F1 hybrid with any one of its parent.
2.Define law of independent assortment?
. The law of independent assortment is a principle of inheritance that each heritable allele is inherited independently of one another.
3.Define law of dominance?
a. The law of dominance "when two alleles of an inherited pair is heterozygous,then the allele that is expressed is dominant whereas the allele that is not expressed is recessive".
4)Define linkage and crossing over?
Ans) Linkage: The tendency of genes remain together in the same chromosome is called linkage. Two (or) more genes carry on a particular chromosome are called linked genes. All the genes on a pair of homologous chromosomes collectively form linkage group.
Crossing over:The exchange of chromosomal segments between two non sister chromatids is called crossing over.The term crossing over coined by T.H Morgan in 1912.Recombinations occurs during meiosis because of crossing over .
5)Define Coupling and Repulsion theory?
Ans)Coupling theory:If two alleles such as 'AB' come from the same parent(AABB×aabb) then they will enter into the same gamates and transmit together.This is called coupling theory.
Repulsion theory: When the same alleles (A&B) come from the different parents(AAbb×aaBB) then they will enter into different gamates at the time of gametogenesis. This is called repulsion theory.
UNIT-4
ReplyDeleteUNIT-4
PLANT BREEDING
1.Define acclimitization?
.Adjustment of introduced plants in new locality a changed climatic condition.such plants are disease resistance due to change in environment but chances to adultrent seeds.
Eg:Parthenon Hysterophorous
Argentina Mexicana
2.Define clonal selection ?
.A variety that is propagated vegetative from a single plant is clone of a single plant obtained by sexual reproduction or all vegetative progenies of a single plant is called a clone.
3.What is Plant Breeding? Give any two objectives.
Ans). Plant breeding is the process by which humans change the characteristics of plants over time to make them better crops and more nourishing food. In its most simple form, breeding consists of selecting the best plants in a given field, growing them to full seed and then using that seed to grow further generations.
Objectives:The main objectives are
i.High Yielding
ii.Disease Resistance
4.Define hybridization ?
.The mating or crossing of two plants or lines of dissimilar genotype is called hybridization
Objectives:
1.To create genetic variation.
2.segregation and recombination produce many new gene combination.
5.Define Mass line,Pure line, Clonal selection?
Ans) Mass line selection:
It can be defined as selection of a number of phenotypically superior seeds from the field population harvesting and bulking their produce together for sowing the next year's crop and process is repeated till desirable characters are achieved.
Pure line selection:
It can be defined as the process of isolating a desirable homozygous individuals from the mixed population and multiplying the same without contamination to release as a new variety.
Clonal selection:
A variety that is propagated vegetative from single parent is called clone. Selection of Desirable clones from the mixed population of vegetative propagated crops called clonal selection.
UNIT-5
ReplyDelete1.Expand RFLP and mention it's objectives?
Ans).RFLP-Restriction Fragment Length Polymorphism
Objectives:
i.Allow the transfer of novel genes from related wild species.
ii.Establish genetic relationships between sexually incompatible crop plants.
2..Define Somaclonal Variations?
Ans).Somaclonal variation is the variation seen in plants that have been produced by plant tissue culture. Chromosomal rearrangements are an important source of this variation.
Objectives:
i.Somaclonal variation leads to the creation of additional genetic variability.
ii.The major likely benefit of somaclonal variation is plant improvement.
3. 1)What is chromosomal mutations?Types of chromosomal mutations?
Ans) A chromosmal mutation is any change or error that occurs within the chromosome.this occurs during cell processes like mitosis and and meiosis
Types:
1)Deletion:Removal of small part.
2)Inversion: Reattachment of same chromosome.
4. what is mutagen? Agents of mutagens?
Ans) The agent that significantly increases the mutation is called mutagen.
Agents:
1)Physical mutagens:
A) UV radiation.
B) Electromagnetic radiation
C) Corpuscular radiation
5.DNA markers? And role in plant breeding?
Ans) It is a fragment of DNA that is associated with in the genome in order to trace genetic alternations especially in the branch of biotechnology and molecular biology.DNA markers are used to identify particular sequence of DNA in a pool of unknown DNA.
Ex:RFLP,RAPD.
SUBMITED BY-DB:22(P.HARIKA)
Unit-3:Mendelian Inheritance
ReplyDelete1)Define test cross & back cross ?
A)Test cross:The cross between F1 hybrid with its recessive parent.
Back cross :If a cross is made between F1 hybrid with any one of its parent.
2)Define Coupling and Repulsion theory?
A)Coupling theory:If two alleles such as 'AB' come from the same parent(AABB×aabb) then they will enter into the same gamates and transmit together.This is called coupling theory.
Repulsion theory: When the same alleles (A&B) come from the different parents(AAbb×aaBB) then they will enter into different gamates at the time of gametogenesis. This is called repulsion theory.
3)Define law of Dominance?
A)Mendel's law stating that when two alleles of an inherited pair is heterozygous, then, the allele that is expressed is dominant whereas the allele that is not expressed is recessive. The expression of the dominant allele suppressing the recessive allele is termed as Law of Dominance.
4)Define the second law of Mendelian Inheritance?
A)The second law of Mendelian Inheritance is The Law of Independant Assortment of Gametes which states that "When two or more characteristics are inherited, individual hereditary factors assort independently during gamete production, giving different traits an equal opportunity of occurring together."
5)Define Complete Linkage and Incomplete Linkage?
A)Complete Linkage: It is defined as the state in which two loci are so close together that alleles of these loci are virtually never separated by crossing over. The closer the physical location of two genes on the DNA, the less likely they are to be separated by a crossing-over event.
Incomplete Linkage:When the genes were loosly linked on a chromosome and show higher percentage of recombination. In such condition non parental type of gametes are formed.
Incomplete linkage produces new combinations of the genes in the progeny due to the formation of chiasma or crossing over in between the linked genes present on homologous chromosomes.
Submitted by:
P.Manikanta,
DB-51.
Unit-4:Plant Breeding
ReplyDelete1)Define plant breeding and mention two objectives?
A)The phenomenon of development of new varieties of plants possessing desirable characters from the already existing varieties .
Objectives:
1.To obtain high yielding variety .
2.To improve disease,drought resistance.
2)Define hybridization ?
A)Th mating or crossing of two plants or lines of dissimilar genotype is called hybridization .
Objectives:
1.To create genetic variation.
2.segregation and recombination produce many new gene combination.
3)What is Acclimatisation?
A)It is a phenomenon of which the individual plant species adapt to the surrounding environmental conditions.
4)Define pure line selection ?
A)It can be defined as the process of isolating a desirable homozygous individual from the mixed population and multiplying the same without contamination to release as a new variety.
5)Define clonal selection ?
A) A variety that is propagated vegetative from a single plant is clone of a single plant obtained by sexual reproduction or all vegetative progenies of a single plant is called a clone.
Unit-5:Breeding,Crop Improvement and Biotechnology
ReplyDelete1)Define mutagen ?write any two types of agents ?
A)The physical or chemical agents which greatly enhance the mutation is called mutagen.
Physical mutagen- uv radiation
Chemical mutagen -N- Nitroso N-methyl urea.
2) Define spontaneous and induced mutations?
A) Spontaneous mutation:If change caused by radiation in a DNA structure.
Induced mutation:Change caused by radiation (or) environmental mutagen.
3)what are DNA markers? Describe its role in plant breeding?
A) It is a fragment of DNA that is associated with in the genome in order to trace genetic alternations especially in the branch of biotechnology and molecular biology.DNA markers are used to identify particular sequence of DNA in a pool of unknown DNA.
Ex:RFLP,RAPD.
4)Expand RFLP,RAPD?
A)RFLP: Restriction fragments length polymorphism.
RAPD: Rapid amplifier polymorphic DNA.
5)Define Molecular Breeding?
A)Molecular breeding is defined as a branch of plant breeding which utilizes molecular genetic tools and approaches for genetic improvement of crop plants. In other words, genetic improvement of crop plants for various economic traits using molecular marker and transformation technologies is referred to as molecular plant breeding.
Submitted by:
P.Manikanta,
DB-51.
G.SNEHA,DB-28
ReplyDelete1.Plasmid:
In addition to the nucleoid,bacterial cytoplasm normally contains one or more circular molecules of double stranded DNA called plasmids.
2.Mesosomes:
In bacterial cells, the plasma membrane shows infoldings invading the cytoplasm. It took part in respiration in mitochondria.
3.Mitochondria :
It is a double membrane bounded cell organelle having disc shaped. The inner membrane contains several infoldings called cristae.it is the power house of the cell.
4.Suicidal bags :
During starvation the lysosomes kill themselves and release undigested food matetial .
5.Nucleosome model :
The chromosomes are in the form of chromatin material and appears like a bead like structure called nucleisome. It contains four basic histone proteins and form octamer.
6.Mitochondria called semi autonomous cell organelle because they have their own DNA and ribosomes that are able to make their own proteins.
Chloroplast called semi autonomous cell organelle because have chlorophyll photosynthetic plants make own food.
7.euchromatin:light staining part of DNA. It is generally active and loosely coiled.
Heterochromatin:darkly stained portion of chromatin.dna is densely coiled and genetically inert.
8.Nucleottide:sugars +nitrogen bases+phosphate.
Nucleoside:nitrogen bases+phosphates.
9.semi conservative replication :
This would produce two copies that each contained one of the original strands and one new strand. This would leave the two original template DNA strands together in a double helix produce copy composed of two new strands.
10.DNA:
Double stranded molecule.
Deoxyribose sugar.
Contains T as nitrogenous base.
It is the hereditory material in the nucleolous of the cells.
Rna:
Single stranded nucleic acid
Contains ribose sugar
Involved in protein synthesis
Both in nucleus and cytoplasm
G.SNEHA,DB-28
ReplyDelete11.Test cross:
Cross f1hybrid with its recessive parent.
Back cross:
Cross between f1 hybrid with any one of its parents.
12.linkage:
The tendency of genes to remain together in the same chromosome.
Crossing over:
Exchange of chromosomal segments between non sister chromatids.
13.coupling:
If two alleles such as A and B come from the same parent (AABB*aabb)then they enter into same gametes and transmit together.
Repulsion:
If two alleles come from the different parents(AAbb*aaBB)enter into different gametes at the time of gametogenesis.
14.Plant breeding:
Phenomena of development of new varieties of plants possessing desirable characters from the already existing varieties.
Objectives:
Obtain high yield variety.
Improve quality, size, shape, colour, taste.
Improve disease, drought and pest resistance.
15.emasculation:
Removal of male sex organ without any damage to female reproductive organ.
16.Acclimitisation:
The newly introduced varieties has to adopt or adjust itself to the changed climatic conditions.
17.hybridisation:
Crossing of two plants of dissimilar genotype.
Objectives:
To crate genetic variation.
Segregation and recombination produce many new gene.
18.types of chromosomal mutations:
1.deletion:remove of small part
2.inversion:reattachment of same chromosome
3.translocation:repetation of same gene sequence
4.nondisjunction:transfer of a part of chromosome to another
5.duplication:failure of chromosomes to separate during meiosis.
19.inbreed lines:
Production of offsprings from the mating of individuals that are closely related genetically.
20.Mutages:
The physical or chemical agent significantly increases the mutation.
Physical mutagens:radiation and heat
Chemical mutagens:basic analogs, alkylating agents, metals, deaminating agents, intercalating agents
Dear Sneha,
DeleteCheck the Emasculation defination
G.SNEHA,DB-28
ReplyDelete21.RFLP:restriction fragment length polymorphism
Objectives:
Allow the transfer of novel genes from related wild species.
Establish genetic relationships between sexually incomparable crop plants.
22.RAPD:random amplified polymorphic dna
Objectives:
These markers are employed in the construction of genetic map.
Used to distinguish between variety based on difference in DNA sequence
23.watson and crick model:
They proposed a model for DNA structure called double helix model. On the basis of this model DNA is made up of two polynucleottide chains.
24.cell brain:
Nucleus is called cellbrain because all the functions of the cell are under the control of the nucleus inside the cell.
25 .mass selection :
Number of phenotypically superior plants from field population harvesting and bulking produce together for next year's crop and repeating process till desired characters are achieved.
Pureline selection:
Process of isolating a desirable homozygous individual from mixed population and multiplying the same without contamination to release as a new variety.
Clonal selection:
A variety is propagated vegetative from a single plant called clone or single plant obtained by asexual reproduction.
Good Sneha,
DeleteStudy well.