The Dept. of
Biotechnology of our College is going to organize a DBT, (Govt. of India, New
Delhi) sponsored One Day hands on Training programme for students and public, in collaboration with Tanusree
Mushroom Cultivars and Eenadu paper on 8th Sep, 2018, on
“MUSHROOM CULTIVATION”
Resource Persons: 1. Mr. T. Jaya
Chandra
(Tanusree Mushroom Cultivars)
2. Dr. B. Siva Kumari,
(Dept. of Botany, ALC)
Organizing Secretaries: Dr. P. Srinivasarao (Botany)
Ms. V. Kavitha (HoD Biotechnology)
Venue: Biotechnology
Lab
Medam who coined the term fertilisation
ReplyDeleteMedam who coined the term fertilisation
ReplyDeleteO. Hertwig
ReplyDeleteN. Prathyusha.
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Unit-1,short Questions. .
1.plasmid:-A plasmid is a small DNA molecule with in 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 in only in the 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.Nuclesome model:-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.
5.cell theory :-A theory in biology that includes one or both of the statements that the cell is the fundamental structural and functional unit of living matter and that the organism is composed of autonomous cells with its properties being the some of those of its cells.
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N. Prathyusha.
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Submitting assignment
Unit-1 questions
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 standarded DNA molecules in bacteria ,however plasmids are sometimes present in archeae 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 suicidal bags because when there is lack of oxygen and food they break to release the enzymes which digest the whole cell.
4.:Nuclosome 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.
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Unit -3
1.Dominant character :- It is the phenomenon where the characters are expressed phenotypically both in homozygous condition and in heterozygous condition is called dominant character.
Eg) :tall-dwarf-height.
Round -wrinkle-shape.
Recessive character :-The character which is not expressed phenotypically in heterozygous condition .
Eg) :Dwarf -height of the plant.
Wrinkled-shape of the plant.
2.Back cross:-If a cross is made between F1-hybrid with any one of its parent.
Test cross:-The cross between F1-hybrid with it's recessive parent is called test cross.
3.Monohybrid cross:-If a cross is made between two individuals differ in one character.
Dihybrid cross:-If a cross is made between two individuals differ in two contrasting characters.
4.Homozygous condition :-An organism is having two similar or identical alleles for a single character (T, t).
Heterozygous condition :-An individual having two different types of alleles for a single character.
Gene:-It is the unit of inheritance and it contains the information required to express the character (A few nucleotide sequence of the DNA is called Gene).
5.Law of segregation :-Mendels 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. .
N. Prathyusha.
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Unit-4
1.Hybridization:- The mating or crossing of two plants or lines of dissimilar genotype is known as Hybridization.
Obejectives:-
* To create genetic variation, when two genotypically different plants are brought together inF1.
*Segregation and recombination produce many new gene combinations in F2 and later generations ,I. e., the segregating generations.
*The degree of variation produced in the segregating generations would, therefore, depend upon the number of genes for which the two parents differ.
2.Acclimatization:- Adjustment of introduced plant in a new locality and changed climatic conditions. Such plants are disease resistant due changed environment but chances of adulterant seeds.
Eg) :-parthenium hysterophorous ,Argemone Mexicana.
3.Plant breeding :- It is the simplest and oldest breeding method. It is also called as German method or German method of broad breeding because once it was used nicely in Germany for improving the sugar beets and small grains such as rye and wheat.
It can be defined as preservation of certain individual plants of desirable characters. In simplest form selection means choosing pants of one's choice. It is basis Of all crop improvement .Even today it is most common method of crop improvement among the cultivators.
4.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 years crop and repeating this process till desired 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 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.Emasculation:-In case of hybridization programme for self-pollination 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 organs is known as Emasculation.
Bagging:- Immediately after emasculation, the flower or the inflorescence is enclosed in suitable bag to prevent random cross pollination. The bags may be made if 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 with in the bag so fungus may develop, which may be prevented by removing the bag after 2-3days after pollination.
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Unit -5
1. DNA markers:- It is a small sequence of known DNA. That is enclosed in a molecular biology and biotechnology to identify the sequence of genome in a pool of unknown DNA.
2.RFLP-Restriction fragment length polymorphism.
RAPD-Rapid amplified polymorphic DNA.
3.Mutations definition :-In general it refers to sudden heritable change in the phenotype if an individual . In molecular term, it is defined as the permanent and relatively rare change in number or sequence of nucleotides .
4.Mutagens:-Mutagens are the physical or chemical agents which greatly enhance the mutations.
Types of mutagens are physical, chemical and biological.
5.somaclonal variations :-The genetic variations found in the invitro cultured cells are collectively referred as somaclonal variations.
The plants derived from such cells are referred to as somaclones. According to few scientists calliclones and protoclones are used to represent the cultures obtained from callus and protoplasm respectively.
N. Prathyusha.
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Unit-2
1.components and chemical composition of DNA:-DNA has 3types of chemical components, phosphate, a sugar called deoxyribose and four nitrogen bases -adenine ,guanine, cytosine and thymin. 2 of the bases, adenine and 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 nucleoside linked to a phosphate group. Nucleotides form 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:- *Watson and crick discovered the structure of DNA.
*They worked together on studying the stage DNA.
*The molecule that contains the hereditary information of the cells.
* They got noble price for thier work on DNA.
5.Difference between DNA and RNA. :-* DNA contains the sugar deoxyribose, while RNA contains the sugar ribose
.The only difference between ribose and deoxyribose is that ribose has one more -OH group than deoxyribose, which has-H attached to the second carbon in the ring.
*DNA is the double stranded molecule which RNA is a single stranded molecule.
*DNA is stable under alkaline conditions while RNA is not stable.
*DNA and RNA perform different functions in humans.DNA Is responsible for sharing and transferring genetic information while RNA directly codes for amino acid and as acts as a manager between DNA and ribosomes to make proteins
Db 43 assinment unit .1 D.jagadeesh kumar
ReplyDelete1 what is plasmid. ?
It is circular ring like structure that can replicate indeped ently of the chrmosomes
2 mesosomes?
They are finger like projections arises from plasma membrane act has a respirarory substrat
3 semi auto somal cell orgnells?
Single circular naked dna and 70s type of ribosomes
4 cell brain?
Neclus is called cell brain
Its structure is called nucleoluesa it contain chromatin
Db43 D.jagadeesh kumar
ReplyDeleteUnit 5
1 define Rapd ?
Rapid amlified polymorpicDNA
2 RFLP?
Restrction fragments length polymorpism
3. Dna markers?
It is gene are dna sequence with known location that can be used to identify indiviual or species
Unit 1 db 43 d.jagadeesh kumar
ReplyDeleteWhat is plasmid?
It is circular ring like structure that replicste independentlg of the chrmosome
2.mesomes?
They are finger like projections arises from plasma membrane they act has a respiratory substrate
3.semi autosomalcellorgnals?
This are single circular naked dna and 70s type of ribosomes
4.power house of the cell?
Mitochondria is called power house of the cell it conducts all cell functions like respiration etc
5.what is cell brain?
Nuclease is called cell brain its struture is called nuceloluss it contains chomatin and it develops in to chrmosome
Unit 1db43
ReplyDelete1.Plasmid?
It is a circular ring like structure that can replicate of chromosome
2.mesomes?
They are finger like projections arises from plasama membrane they act as rspiratlry substrat
3.semiautosomal cell organals?
This are circulr nakwd dna and 70s type of ribosomes
4.power house of the cell?
Mitochondria is called power house of the cell has takw care functions of the xell
5.cell brain?
Nuclease is calles cell brain it contain chromatin and it devlops into chrmosomes
Unit5. Db43
ReplyDelete1.Define RAPD?
Rapid amplification polymopic dna
2.RFLP?
Restrion fragments length polymorphism
3.DNA markers it a gene sequence with known location that can be need to identify indiviual or species
Unit 3. Db43
ReplyDelete1.what monohybrid and dihybrid cross?
Monohybrid it s cross made between two individuals differ by one character
Dihybrid. Cross made between t.wo indivials differ in two cotrasting characters
2.what is gene?
Unit of heeitance contains information required to express character
3.dominent and ressive?
Dominent where character expressed phenotipically both in homozogous and heterozogous condition
Tall dwarf . ..height
Round and wrinkle. ...shape
Recessive. Which is not expressed phenotipically in heterozogous condition
4. Phenotype and genotype?
Phenotype . Physical or morphological apperance
Genotype..ganatic make of an individual
5. G.j .mendal?
He called father of genectics he is monk he is mathmatician he the frist person to study the genotipicall changes
Unit 4. Db43
ReplyDelete1.plant breeding and objectives?
Branch of botany that deals With the improvement or plants different aspects
Objects:optain hi yeilding plants
Improve quality size shape and colour
Improve disease drough disease resistant
2.emasulation?
Removal of male sex organs of a selected flower with out causing any damage to female sex organ
3.hybridiztion and types of hybridization?
Mating of o f two plants or disimilar genotype is known has hybridization
Types
Intra variental hybridization
Inntervariental hybrization
Inter spefic hybrization
Inter genic hybrization
4. Mass selection?
Selection of phenotipically superior plants for harvesting and bulking to gether to produce high quality plants
5.pureline seletion and clonal selection?
Process of isolating desrible no of homozogous individual from mixed population without contamination of gamets are released new varietyinto market is called pureline selection
Colonal selection.. Propagating of plants from single plant is called clone this are obtained from asexual reproduction the fromed one is same as parent
Unit 2. Db43
ReplyDelete1.Watson and crick?
They weee the frist person to propse the structure of dna ,double stranded it contains protein part they gave digramatic represation for that they were awarded noble prize
2.semi conservative made or replication.?
Saparation of two parental strands act has a template each new template from the two new dna strnds one is old and one is new
3.nucelotide?
Compound consisting of a nucleoside linked to a phospate group
4.satellite chromosomes ?
It is present on the chrmosome it a prest like beed like structure hence it is called satellite chrmosomes
5.types of chrmosomes based on position?
Metacentric ,submete centric,arcocentric,telocentric type of chrmosomes
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P.Harika.
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Submitting assignment
Unit-1
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 strand DNA molecule in bacteria, however plasmids are sometimes present in archeae of eukaryotic organism.
2.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 protein core.this structure is often compared to thread wrapped around a spool.
3.Cell theory:- A theory in biology that include one or both of the statements that the cell is the fundamental structural and functional unit of living matter and the organism is composed of autonomous cell with its properties being the sum of those of its cells.
4.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 material from entering through it in other words its selective materials that can enter the cell.that the reason it is called as selectively permeable membrane.
5.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.
ReplyDeleteUnit-1 questions
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 standarded DNA molecules in bacteria ,however plasmids are sometimes present in archeae 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 suicidal bags because when there is lack of oxygen and food they break to release the enzymes which digest the whole cell.
4.:Nuclosome 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.
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1.Define nucleosome model?
ReplyDelete.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.
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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.
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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.
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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
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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.
ReplyDeleteThey 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.
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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.
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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.
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WHAT IS T,C, A AND G
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.
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WHAT IS T,C, A AND G
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.
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NO NEED OF DOUBLE SPACE BETWEEN THE QUESTIONS
WHAT IS T,C, A AND G
Good afetnoon Mam, this K.Amarnath reddy, NB-49, submitting my botany assignment on embryology.
ReplyDelete1.define embroyology? name eminent indian embryologists?
A.the branch of biology and medicine concerned with the study of embryos and their development.
samo of the eminent indian embryologists are:1. Johannes Peter Muller(1801-1858) 2. Julius Kollmann(1834-1918) 3. Hans Spemann(1869-1941)
2.Define Tapetum?
A. The tapetum is a specialised layer of nutritive cells found within the anther, of flowering plants, where it is located between the sporangenous tissue and the anther wall. Tapetum is important for the nutrition and development of pollen grains, as well as a source of precursors for the pollen coat.
3.Define Endothecium?
A. In angiosperms, the layer of cells lying beneath the epidermis of the wall of the anther. As the anther matures, thickenings often develop in the cell walls of the endothecium, probably aiding dehiscence.
4.Define microspore?
A. Microspores are land plant spores that develop into male gametophytes, whereas megaspores develop into female gametophytes. The male gametophyte gives rise to sperm cells, which are used for fertilization of an egg cell to form a zygote.
5. Define Palaenology?
A. Palynology is the study of plant pollen, spores and certain microscopic plankton organisms in both living and fossil form.
6. Define megasporangium? and mention types in it?
A. the structure in certain spore-bearing plants in which the megaspores are formed.
Megagametophytes of flowering plants may be described according to the number of megaspores developing, as either monosporic, bisporic, or tetrasporic. these are the types of megasporangium.
7. define monosporic, bisporoic, tetrasporic types of embryo sac?
A. Based on the number of megaspores, embryo sacs can be divided into three types: monosporic, bisporic, and tetrasporic.
1.monosporic type: it is also known as Polygonum-type embryo sac, meiosis of the diploid megaspore mother cell in the nucellus produces four haploid megaspores. Three of the megaspores, usually those at the micropylar end of the nucellus, subsequently undergo programmed cell death, leaving only one functional megaspore.
2.bisporic type: bisporic embryo sacs, meiosis produces only two megaspores, each containing two haploid nuclei, due to the absence of cytokinesis and cell plate formation following the second meiotic division. The megaspore nearest the micropyle then undergoes programmed cell death, leaving a single functional megaspore with two haploid nuclei.
3. tetrasporic type: In tetrasporic embryo sacs, cell plates fail to form after both meiotic divisions, resulting in a single four-nucleate megaspore.
8.define the terms fertilization and syngamy? and name the scientists who coined dthe names?
A. fertilisation: Fertilisation is fusion of gametes to form a new organism of the same species. Wilhelm August Oscar Hertwig(1849-1922) discovered fertilisation
syngamy: a method of reproduction in which two individuals (gametes) unite permanently and their nuclei fuse.Kondrashov coined the name. it is considered as the modified form of the fertilisation.
9. Define double fertilisation and triple fusion?
A. double fertilisation: fertilization characteristic of seed plants in which one sperm nucleus fuses with the egg nucleus to form an embryo and another fuses with polar nuclei to form endosperm.
triple fusion: the fusion involving two polar nuclei and a sperm nucleus that occurs in double fertilization in a seed plant and results in the formation of the endosperm.
10. Define endosperm? mention the types in it.
A. a nutritive tissue in seed plants formed within the embryo sac by division of the endosperm nucleus. Three main types of endosperm development in flowering plants are: 1.Nuclear type. 2.Cellular type and 3.Helobial type.
K.Amarnath Reddy,
DeleteGOOD
Good afternoon Mam, this K.Amarnath reddy NB-49, submitting my remaining botany assignment on embryology.
ReplyDelete10. Define endosperm? mention the types in it.
A. a nutritive tissue in seed plants formed within the embryo sac by division of the endosperm nucleus. Three main types of endosperm development in flowering plants are: 1.Nuclear type. 2.Cellular type and 3.Helobial type.
11. Define ruminate endosperm?
A. the condition in which the endosperm is dissected by in-growths of the seed coat, is a common condition in the palms.
12. Define Helobial type of endosperm?
A. It is an intermediate type between the nuclear and cellular types. The first division is accompanied by cytokinesis but the subsequent ones are free nuclear. The chamber towards micropylar end of embryo sac is usually much larger than the chamber towards chalazal end.
13.Mention the differences between dicot and monocot embryos?
A. Monocots : 1. contains one cotyledon
2. usually parallel venation
3. vascular bundales are usually complexy arranged.
4. fibrous root system is present
5. floral parts are usually in multiples of three
Dicots : 1. contains 2 cotyledons
2. usually veins are network like
3. vascular bundles are usually arranged in rings
4. tap root system is present
5. floral parts are usually in the multiples of four or five
14. Define scutellum?
A. The large, shield-shaped cotyledon of the embryo of a grass plant, specialized for the absorption of food from the endosperm.The scutellum is considered to represent the first leaf or cotyledon.
15. Define polyembryony?
A. the production of more than one embryo from one egg is known as polyembryony.
DEAR K.Amarnath reddy
DeleteGOOD, MENTION THE EXAMPLE FOR RUMINATE ENDOSPERM
mam this is NB29 [T.HIMAJA]
ReplyDelete1:EMBRYOLOGY:
The branch of biology which deals with the study of the development of gametes;fertilization and development of embryos is called embryology
Reinier de graaf;karl von baer;Robert remark are some of the Indian eminent embryologists.
2:TAPETUM:
The inner tissue of sporangium which is nutritive in function to the developing spores inside the anther is called tapetum.
3:ENDOTHECIUM :
The inner mass of the cells present inside the anther below the epidermis helps in dehisence of spores is called endothecium.
4.MICROSPORE:
The spores which develop into male gametes after microsporogenesis are called microspores.(pollen grains)
5: pALYNOlOGY:
The study of the pollen grains,spores and microscopic organs of the plant body is called palenology.
6: MEGASPORANGIUM :
The sporangium that yeilds the female gametes [ovules] after megasporogenesis is called megasporangium.
TYPES:
1.orthotropous ovule.
2.anatropous ovule.
3.hemi anatropous ovule.
4.campylotropous ovule.
5.circinotropous ovule.
6.amphitropous ovule.
7: 1.MONOSPORIC EMBRYO:
The embryo formed from the single spore that is produced from the megaspore mother cell after reduction division is called monosporic embryo.
2.BISPORIC EMBRYO :
The embryo formed from the two spores that are produced from the megaspore mother cell after meiosis is caller bisporic embryo.
3.TETRASPORIC EMBRYO:
The embryo formed from the tetrad that are produced from the megaspore mother cells ater meiosis is called tetrasporic embryo.
8: FERTILISATION/SYNGAMY :
Fertilisation is the fusion of the male and female gametes to initiate the development of individual is called fertilisatin.
oscor hertwig coined the term fertilisation.
9. 1:DOUBLE FERTILISATIN:
The fusion of the haploid male gamete with the haploid egg cell in the ovule is called double fertilisation.
2:TRIPLE FISION:
The fusion of the haploid male gamete with the diploid nucleus to form the primary endosperm nucleus[PEN] is called triple fusion.
10.ENDOSPERM:
The nutritive tissue produced inside the seeds of the flowering plants after fertilisation is called endosperm.
TYPES:
1.nuclear endosperm.
2.cellular endosperm.
3. helobial endosperm.
11.RUMINATE ENDOSPERM:
The endosperm which is dissected by in-growths of the seed coat is called ruminate endosperm.
12.HELOBIAL ENDOSPERM:
The endosperm which is having half cellular pattern and other half nuclear pattern is called helobial endosperm
13: DICOT : MONOCOT
1.Two cotyledons 1.single cotyledon
2. scutellum absent 2. scutellum present
3. reticulate venation 3. parallel venation
4. tap root system 4. adventitious system
14: SCUTELLUM :
The modified thin cotyledon in monocots which serves to absorb nutrients from the endosperm is called scutellum
15: POLYEMBRONY:
The formation of more than one embryo from a single fertilized ovum is called polyembryony
16:OBJECTIVES OF POLYEMBRYONY:
1.To increase the probability of survival under varied conditions.
2.Formation of more than one embryosacs within the same ovule.
3.High density cultivation of plants.
DEAR T.HIMAJA,
DeleteTAPETUM, ENDOTHECIUM, MICROSPORE NOTES NOT SUFFICIENT.
MENTION THE EXAMPLES FOR TYPES OF OVULES
Hello Madam, This is B.Mary Priyanka (NB-54)
Delete1.EMBRYOLOGY
The science dealing with the formation, structure, and functional activities of embryos. Panchanan Maheshwari rose to become one of the most distinguished embryologists not only in India but of the world.
12. HELOBIAL ENDOSPERM:
DeleteThis type of endosperm occurs in the order Helobiales. In this case, 1st division of primary endosperm nucleus is followed by a transverse wall. This wall divides the embryo sac into a small chalazal chamber and a large micropylarhe nuclei in each chamber divide by free nuclear divisions.But, there are fewnuclear divisions in the chalazal chamber. The endospem in this chamber degenerate. Walls develop between nuclei in micropylar chamber, it produces cellular endosperm.
13. DICOT MONOCOT
Delete2 cotyledons 1 cotyledon
pumule distal pumule lateral
coleoptile and coleorhiza absent coleoptile and coleorhiza present
scutellum absent scutellum present
14. SCUTELLUM
DeleteIt is a shield like cotyledon of certain monocots.It is situated towards lateral side of embryonal axis. This axis at its lower end has radicle and root cap enclosed in a sheath called coleorhiza.
15.POLYEMBRYONY
DeleteIt is the phenomenon of production of more than one embryo from one egg.
16. OBJECTIVES OF POLYEMBRYONY
DeleteA.This helps in survival under varied conditions.
B.More than one embryo sac is formed within the ovule.
C. It increases density of plant growth.
DEAR PRIYANKA,
DeleteGOOD
This is abhilash bhupathi nb 09 botany assignment 01
ReplyDelete1.define embroyology? name eminent indian embryologists?
A.the branch of biology and medicine concerned with the study of embryos and their development.
samo of the eminent indian embryologists are:1. Johannes Peter Muller(1801-1858) 2. Julius Kollmann(1834-1918) 3. Hans Spemann(1869-1941)
2.Define Tapetum?
A. The tapetum is a specialised layer of nutritive cells found within the anther, of flowering plants, where it is located between the sporangenous tissue and the anther wall. Tapetum is important for the nutrition and development of pollen grains, as well as a source of precursors for the pollen coat.
3.Define Endothecium?
A. In angiosperms, the layer of cells lying beneath the epidermis of the wall of the anther. As the anther matures, thickenings often develop in the cell walls of the endothecium, probably aiding dehiscence.
4.Define microspore?
A. Microspores are land plant spores that develop into male gametophytes, whereas megaspores develop into female gametophytes. The male gametophyte gives rise to sperm cells, which are used for fertilization of an egg cell to form a zygote.
5. Define Palaenology?
A. Palynology is the study of plant pollen, spores and certain microscopic plankton organisms in both living and fossil form.
6. Define megasporangium? and mention types in it?
A. the structure in certain spore-bearing plants in which the megaspores are formed.
Megagametophytes of flowering plants may be described according to the number of megaspores developing, as either monosporic, bisporic, or tetrasporic. these are the types of megasporangium.
7. define monosporic, bisporoic, tetrasporic types of embryo sac?
A. Based on the number of megaspores, embryo sacs can be divided into three types: monosporic, bisporic, and tetrasporic.
1.monosporic type: it is also known as Polygonum-type embryo sac, meiosis of the diploid megaspore mother cell in the nucellus produces four haploid megaspores. Three of the megaspores, usually those at the micropylar end of the nucellus, subsequently undergo programmed cell death, leaving only one functional megaspore.
2.bisporic type: bisporic embryo sacs, meiosis produces only two megaspores, each containing two haploid nuclei, due to the absence of cytokinesis and cell plate formation following the second meiotic division. The megaspore nearest the micropyle then undergoes programmed cell death, leaving a single functional megaspore with two haploid nuclei.
3. tetrasporic type: In tetrasporic embryo sacs, cell plates fail to form after both meiotic divisions, resulting in a single four-nucleate megaspore.
DEAR abhilash bhupathi nb 09
DeleteWRITE YOUR NAME PROPERLY
This is abhilash bhupathi nb 09 remaining assignment questions from 8to16
ReplyDelete8: FERTILISATION/SYNGAMY :
Fertilisation is the fusion of the male and female gametes to initiate the development of individual is called fertilisatin.
oscor hertwig coined the term fertilisation.
9. 1:DOUBLE FERTILISATIN:
The fusion of the haploid male gamete with the haploid egg cell in the ovule is called double fertilisation.
2:TRIPLE FISION:
The fusion of the haploid male gamete with the diploid nucleus to form the primary endosperm nucleus[PEN] is called triple fusion.
10.ENDOSPERM:
The nutritive tissue produced inside the seeds of the flowering plants after fertilisation is called endosperm.
TYPES:
1.nuclear endosperm.
2.cellular endosperm.
3. helobial endosperm.
11.RUMINATE ENDOSPERM:
The endosperm which is dissected by in-growths of the seed coat is called ruminate endosperm.
12.HELOBIAL ENDOSPERM:
The endosperm which is having half cellular pattern and other half nuclear pattern is called helobial endosperm
13: DICOT : MONOCOT
1.Two cotyledons 1.single cotyledon
2. scutellum absent 2. scutellum present
3. reticulate venation 3. parallel venation
4. tap root system 4. adventitious system
14: SCUTELLUM :
The modified thin cotyledon in monocots which serves to absorb nutrients from the endosperm is called scutellum
15: POLYEMBRONY:
The formation of more than one embryo from a single fertilized ovum is called polyembryony
16:OBJECTIVES OF POLYEMBRYONY:
1.To increase the probability of survival under varied conditions.
2.Formation of more than one embryosacs within the same ovule.
3.High density cultivation of plants.
Respected Mam I'm p.kiranchandu of NB(57)
ReplyDeleteHope you like my assignment
1)EMBRYOLOGY
Embryology (from Greek ἔμβρυον, embryon, "the unborn, embryo"; and -λογία, -logia) is the branch of biology that studies the prenatal development of gametes
Robert,Heinz Christian Pander,Everett Just, and Edward B. Lewis.
2)TAPETAUM
The tapetum is a specialised layer of nutritive cells found within the anther, of flowering plants, where it is located between the sporangenous tissue and the anther wall. Tapetum is important for the nutrition and development of pollen grains, as well as a source of precursors for the pollen coat.[1]
Two main tapetum types are recognised, secretory (glandular)and plasmodial (amoeboid).
3)ENDOTHECIUM
1. (fibrous layer) In angiosperms, the layer of cells lying beneath the epidermis of the wall of the anther. As the anther matures, thickenings often develop in the cell walls of the endothecium, probably aiding dehiscence.
2. In Bryophyta, the inner layer of cells in the young sporophyte.
4)MICROSPORES
Microspores are land plant spores that develop into male gametophytes, whereas megaspores develop into female gametophytes. The male gametophyte gives rise to sperm cells, which are used for fertilization of an egg cell to form a zygote. Megaspores are structures that are part of the alternation of generations in many seedless vascular cryptogams, all gymnosperms and all angiosperms. Plants with heterosporous life cycles using microspores and megaspores arose independently in several plant groups during the Devonian period.Microspores are haploid, and are produced from diploid microsporocytes by meiosis.
5)PALANOLOGY
Palynology is the "study of dust" (from Greek: παλύνω palunō, "strew, sprinkle"[2] and -logy) or "particles that are strewn". A classic palynologist analyses particulate samples collected from the air, from water, or from deposits including sediments of any age. The condition and identification of those particles, organic and inorganic, give the palynologist clues to the life, environment, and energetic conditions that produced them.
By the late 1870s, as optical microscopes improved and the principles of stratigraphy were worked out, Robert Kidston and P. Reinsch
GOOD, NO NEED OF DOUBLE SPACE.
Delete6)MEGASPORANGIUM
ReplyDeleteIn seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: The integument(s), forming its outer layer(s), the nucellus (or remnant of the megasporangium), and the female gametophyte (formed from a haploid megaspore) in its center. The female gametophyte — specifically termed a megagametophyte— is also called the embryo sac in angiosperms. The megagametophyte produces an egg cell (or several in some groups) for the purpose of fertilization.
Types of ovules
Types of ovule
There are six types of ovules:
1. Orthotropous or atropous ovule
(ortho-straight, tropous - turn)
The body of the ovule is erect or straight. The hilum, chalaza and the micropyle lie in a straight line e.g.Polygonum.
2. Anatropous ovule
(ana - backward or up, tropous - turn)
The body of the ovule becomes completely inverted during the development so that the micropyle lies very close to the hilum (eg) Gamopetalae members.
3. Hemi-anatropous or hemitropous ovule
The body of the ovule is placed transversely at right angles to the funicle. The micropyle and chalaza lie in one straight line e.g.Ranunculus.
4. Campylotropous ovule
(kampylos - curved)
The body of the ovule is curved or bent round so that the micropyle and chalaza do not lie in the same straight line. e.g. Leguminosae.
5. Amphitropous ovule
The curvature of the ovule is very much pronounced and the embryosac also becomes curved e.g.Allismaceae, and Butomaceae.
6. Circinotropous ovule
The nucellus and the axis are in the same line in the beginning but due to rapid growth on one side, the ovule becomes anatropous. The curvature continues further and the micropyle again points upwards (e.g.) Opuntia.
7)MONOSPORIC,BISPORIC&TETRASPORIC EMBRYO
Monosporic — In this type of development 3 megaspores of tetrad get degenerate one remain functional and forms embryosac.
Bisporic — when two megasporic nuclei takes part in formation of embryosac. Both the nuclei are genetically different.
Tetrasporic — In this type due to failure of cytokinesis I and II a four nucleate coenomegaspore tetrad is formed and all 4 nuclei participate in formation of embryosac.
8)FERTILIZATION
Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, insemination, pollination,[1] fecundation, syngamy and impregnation,[2] is the fusion of gametes to initiate the development of a new individual organism.[3] The cycle of fertilisation and development of new individuals is called sexual reproduction. During double fertilisation in angiosperms the haploid male gamete combines with two haploid polar nuclei to form a triploid primary endosperm nucleus by the process of vegetative fertilisation.
FERTLIZATION IN PLANTS
The gametes that participate in fertilisation of plants are the pollen (male), and the egg (female) cell. Various families of plants have differing methods by which the female gametophyte is fertilized. In Bryophyte land plants, fertilisation takes place within the archegonium. In flowering plants a second fertilisation event involves another sperm cell and the central cell which is a second female gamete. In flowering plants there are two sperm from each pollen grain.
In seed plants, after pollination, a pollen grain germinates, and a pollen tube grows and penetrates the ovule through a tiny pore called a micropyle. The sperm are transferred from the pollen through the pollen tube to the ovule.
DEAR Kiran chandu,
DeleteNO NEED OF DOUBLE SPACE
9)DOUBLE FERTLIZATION
ReplyDeleteDouble fertilization is a complex fertilization mechanism of flowering plants (angiosperms). This process involves the joining of a female gametophyte (megagametophyte, also called the embryo sac) with two male gametes (sperm). It begins when a pollen grain adheres to the stigma of the carpel, the female reproductive structure of a flower. The pollen grain then takes in moisture and begins to germinate, forming a pollen tube that extends down toward the ovary through the style. The tip of the pollen tube then enters the ovary and penetrates through the micropyle opening in the ovule. The pollen tube proceeds to release the two sperm in the megagametophyte.
TRIPLE FISION
Triple fusion is the fusion of the male gamete with two polar nuclei inside the embryo sac of the angiosperm.
This process of fusion takes place inside the embryo sac.
When pollen grains fall on the stigma, they germinate and give rise to the pollen tube that passes through the style and enters into the ovule. After this, the pollen tube enters one of synergids and releases two male gametes there. Out of the two male gametes, one gamete fuses with the nucleus of the egg cell and forms the zygote (syngamy). The other male gamete fuses with the two polar nuclei present in the central cell to form a triploid primary endosperm nucleus. Since this process involves the fusion of three haploid nuclei, it is known as triple fusion. It results in the formation of the endosperm.
One male gamete nucleus and two polar nuclei are involved in this process.
10)ENDOSPERM
The endosperm is the tissue produced inside the seeds of most of the flowering plants following fertilization. It surrounds the embryo and provides nutrition in the form of starch, though it can also contain oils and protein. This can make endosperm a source of nutrition in the human diet. For example, wheat endosperm is ground into flour for bread (the rest of the grain is included as well in whole wheat flour), while barley endosperm is the main source of sugars for beer production. Other examples of endosperm that forms the bulk of the edible portion are coconut "meat" and coconut "water",[1] and corn. Some plants, such as orchids, lack endosperm in their seeds.
Types
(i) Nuclear type:
In nuclear type of endosperm the first division of primary endosperm nucleus and few subsequent nuclear divisions are not accompanied by wall formation. The nuclei produced are free in the cytoplasm of the embryo sac and they may remain free indefinitely or wall formation takes place later. In the coconut, cell wall formation of endosperm is never found complete. In Areca and Phoenix the endosperm becomes very hard (Fig. 2.29 A).
(ii) Cellular type:
In this case, there is cytokinesis after each nuclear division of endosperm nucleus. The endosperm, thus, has a cellular form, from the very beginning because first and subsequent divisions are all accompanied by wall formation e.g. Petunia, Datura, Adoxa, etc. (Fig.2.29C).
(iii) Helobial type:
It is an intermediate type between the nuclear and cellular types. The first division is accompanied by cytokinesis but the subsequent ones are free nuclear. The chamber towards micropylar end of embryo sac is usually much larger than the chamber towards chalazal end.
11)RUMINATE ENDOSPERM
the condition in which the endosperm is dissected by in-growths of the seed coat, is a common condition in the palms.
Ruminate endosperm forms when the seed coat intrudes inward via meristematic growth. In palms, growth of the seed coat may intrude the young endosperm.
12)HELOBAL ENDOSPERM
It is an intermediate type between the nuclear and cellular types. The first division is accompanied by cytokinesis but the subsequent ones are free nuclear. The chamber towards micropylar end of embryo sac is usually much larger than the chamber towards chalazal end.
DEAR KIRAN CHANDU,
DeleteGOOD, STUDY WELL
13)
ReplyDeleteDICOT
Two cotyledons
scutellum absent
reticulate venation
tap root system
MONOCOTS
single cotyledon
scutellum present
parallel venation
adventitious system
14)SCUTELLUM
The scutellum (from the Latin scutella meaning "small shield") can also refer to the equivalence of a thin cotyledon in monocots (especially members of the grass family). It is very thin with high surface area, and serves to absorb nutrients from the endosperm during germination.[2]
The scutellum is believed to contain an as yet unidentified protein transporter that facilitates starch movement from the endosperm to the embryo.
15)POLYEMBRONY
Polyembryony is the phenomenon of two or more embryos developing from a single fertilized egg.[1][2][3] Due to the embryos resulting from the same egg, the embryos are identical to one another, but are genetically diverse from the parents.[1][2] The genetic difference between the offspring and the parents, but the similarity among siblings, are significant distinctions between polyembryony and the process of budding and typical sexual reproduction.[2] Polyembryony can occur in humans, resulting in identical twins, though the process is random and at a low frequency.[1] Polyembryony occurs regularly in many species of vertebrates, invertebrates, and plants.
16)OBJECTIVES OF POLYEMBRYONY:
To increase the probability of survival under varied conditions.
Formation of more than one embryosacs within the same ovule.
High density cultivation of plants.
Hello Madam, This is B.Mary Priyanka (NB-54)
ReplyDelete1. EMBRYOLOGY and EMINENT INDIAN EMBRYOLOGIST
The science dealing with the formation, development, structure,and functional activities of embryos. Panchanan Maheshwari rose to become one of the most distinguished embryologists not only in India but of the entire world. He worked on embryological aspects and popularized the use of embryological characters in taxonomy.
2.Tapetum
A layer of cells often investing the archespore in a developing sporangium and absorbed as the spores mature. It is the inner most wall layer and it nourishes the developing pollen grains. Cells of the tapetum posses dense cytoplasm and generally have more than one nucleus.
3.ENDOTHECIUM
The lining of the cavity of an anther.It performs the function of protection and help in dehiscence of anther to release the pollen. It is below the epidermis and expands radially with fibrous thickenings; at maturity these cells lose water and contract and help in the dehiscence of pollen sacs.
4.MICROSPORE
The smaller of the two kinds of spores characteristically produced by seed plants and some others developing into a male gametophyte. As anthers mature and dehydrate the microspores dissociate from each other and develop into pollen grains.
5.PALYNOLOGY
The study of live and fossil spores, pollen grains and similar plant structures is called palynology.
6.MEGASPORANGIUM AND TYPES
The structure in certain spore bearing plants in which the megaspores are formed: corresponds to the ovule in seed plants.
TYPES
a. Orthotropous ovule.
b. Anatropous ovule.
c. Hemi anatropous ovule.
d. Campylotropous ovule.
e. Cicrcinotropous ovule.
f. Amphitropous ovule.
7. MONOSPORY BISPORY TETRASPORY
a. Monospory: In majority of the flowering plants, one of the megaspores is functional while the other three degenerate.Only the functional megaspore acts as a mothercell for the development of female gametophyte. This method of embryo sac formation from a single megaspore is termed monosporic development.
b. Bisporic- If two of the megaspores are functional while the other two degenerate and the embryo sac is formed from two megaspores it is called as Bisporic development.
c. Tetrasporic- If all the megaspores are functional and participate in the embryo sac formation it is called as tetrasporic mode of develpoment.
8.FERTILIZATION/SYNGAMY
The most vital event of sexual reproduction is perhaps the fusion of gametes. This process called syngamy results in the formation of a diploid zygote. The term fertilization is often used for this process. The terms syngamy and fertilization are frequently used though interchangeably.
DEAR PRIYANKA,
DeleteWRITE FULL QUESTION
GOOD PRESENTATION.
2. TAPETUM
ReplyDeleteA layer of cells often investing the archespore in a developing sporangium and absorbed as the spores mature.It is the inner most layer and it nourishes the developing pollen grains. Cells of the tapetum possess dense cytoplasm and generally have more than one nuclei.
3. ENDOTHECIUM
ReplyDeleteThe lining of the cavity of an anther. It performs the function of protection and help in dehiscence of anther to release the pollen. It expands radially with fibrous thickenings; at maturity these cells lose water and contract and help in dehiscence of pollen sacs.
4.MICROSPORE
ReplyDeleteThe smaller of the two kinds of spores characteristically produced by seed plants and some others developing into a male gametophyte. As the anthers mature and dehydrate the microspores dissociate from each other and develop into pollen grains.
5.PALYNOLOGY
ReplyDeleteThe study of live and fossil spores, pollen grains, and similar plant structures.
6.MEGASPORANGIUM
ReplyDeleteThe structure in certain spore bearing plants in which the megaspores are formed; corresponds to the ovule in seed plants.
TYPES
a. Orthotropous
b. Anatropous
c. Campylotropous
d. Circinotropous
e. Hemitropous
f. Amphitropous
7. MONOSPORY:
ReplyDeleteIn a majority of flowering plants one of the megaspores is functional while the other three degenerate. Only the functional megaspore acts as a mothercell for the develpoment of female gametophyte. This method of embryo sac formation from a single megaspore is termed as monosporic development.
BISPORIC:
If the embryo sac develops from two megaspores and the other two are degenerated, it is called as bisporic type.
TETRASPORIC:
If the embryo sac develops from all the four megaspores it is called as tetrasporic type.
8.FERTILIZATIONL/SYNGAMY
ReplyDeleteThe most vital event of sexual reproduction is perhaps the fusion of gametes. this process is called synagamy results in the formation of a diploid zygote.The term fertilization is aslo often used for this process.The terms synagamy and fertilization are frequently used though interchangeably.
9.DOUBLE FERTILIZATION AND TRIPLE FUSION
ReplyDeleteAfter entering one of the synergids the pollen tube burts and releases the two male gametes into the cytoplasm of the synergid. One of the male gamete fuses with the egg cell and the other fuses with the polar nuclei. This is called as double fertilization an event unique to angiosperms. As one of the gamete fuses with the polar nuclei it involves fusion of three nuclei hence the process is called triple fusion.
10. ENDOSPERM
ReplyDeleteThe central cell after triple fusion becomes the primary endosperm cell and develops into the endosperm while the zygote develops into an embryo. This is a nutritive tissue helps in nourishing the growing embryo.
TYPES
1.Helobial endosperm
2. Cellular endosperm
3. Nuclear endosperm
11. RUMINATE TYPE OF ENDOSPERM
ReplyDeleteRuminate endosperm , the condition in which the endosperm is dissected by in growths of seed coat, is a common condition in plams.
RESPECTED MAM I AM SHAIK ASIF AHAMMED (NB-61)this is my assingment
ReplyDelete1.define embroyology? name eminent indian embryologists?
A.the branch of biology and medicine concerned with the study of embryos and their development.
samo of the eminent indian embryologists are:1. Johannes Peter Muller(1801-1858) 2. Julius Kollmann(1834-1918) 3. Hans Spemann(1869-1941)
2.Define Tapetum?
A. The tapetum is a specialised layer of nutritive cells found within the anther, of flowering plants, where it is located between the sporangenous tissue and the anther wall. Tapetum is important for the nutrition and development of pollen grains, as well as a source of precursors for the pollen coat.
3.Define Endothecium?
A. In angiosperms, the layer of cells lying beneath the epidermis of the wall of the anther. As the anther matures, thickenings often develop in the cell walls of the endothecium, probably aiding dehiscence.
4.Define microspore?
A. Microspores are land plant spores that develop into male gametophytes, whereas megaspores develop into female gametophytes. The male gametophyte gives rise to sperm cells, which are used for fertilization of an egg cell to form a zygote.
5. Define Palaenology?
A. Palynology is the study of plant pollen, spores and certain microscopic plankton organisms in both living and fossil form.
6. Define megasporangium? and mention types in it?
A. the structure in certain spore-bearing plants in which the megaspores are formed.
Megagametophytes of flowering plants may be described according to the number of megaspores developing, as either monosporic, bisporic, or tetrasporic. these are the types of megasporangium.
7. define monosporic, bisporoic, tetrasporic types of embryo sac?
A. Based on the number of megaspores, embryo sacs can be divided into three types: monosporic, bisporic, and tetrasporic.
1.monosporic type: it is also known as Polygonum-type embryo sac, meiosis of the diploid megaspore mother cell in the nucellus produces four haploid megaspores. Three of the megaspores, usually those at the micropylar end of the nucellus, subsequently undergo programmed cell death, leaving only one functional megaspore.
2.bisporic type: bisporic embryo sacs, meiosis produces only two megaspores, each containing two haploid nuclei, due to the absence of cytokinesis and cell plate formation following the second meiotic division. The megaspore nearest the micropyle then undergoes programmed cell death, leaving a single functional megaspore with two haploid nuclei.
3. tetrasporic type: In tetrasporic embryo sacs, cell plates fail to form after both meiotic divisions, resulting in a single four-nucleate megaspore.
8: FERTILISATION/SYNGAMY :
Fertilisation is the fusion of the male and female gametes to initiate the development of individual is called fertilisatin.
oscor hertwig coined the term fertilisation.
9. 1:DOUBLE FERTILISATIN:
The fusion of the haploid male gamete with the haploid egg cell in the ovule is called double fertilisation.
2:TRIPLE FISION:
The fusion of the haploid male gamete with the diploid nucleus to form the primary endosperm nucleus[PEN] is called triple fusion.
10.ENDOSPERM:
The nutritive tissue produced inside the seeds of the flowering plants after fertilisation is called endosperm.
TYPES:
1.nuclear endosperm.
2.cellular endosperm.
3. helobial endosperm.
11.RUMINATE ENDOSPERM:
The endosperm which is dissected by in-growths of the seed coat is called ruminate endosperm.
12.HELOBIAL ENDOSPERM:
The endosperm which is having half cellular pattern and other half nuclear pattern is called helobial endosperm
13: DICOT : MONOCOT
1.Two cotyledons 1.single cotyledon
2. scutellum absent 2. scutellum present
3. reticulate venation 3. parallel venation
4. tap root system 4. adventitious system
14: SCUTELLUM :
The modified thin cotyledon in monocots which serves to absorb nutrients from the endosperm is called scutellum
15: POLYEMBRONY:
The formation of more than one embryo from a single fertilized ovum is called polyembryony.