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Good morning madam I am v. Supriya.NB17,sorry for the late submission because of my grandfather was expired.1)Define Embrology? ? name eminent indian embryologists?A:It is the branch of Biology that deals with the "study of embryos"but in general terms it include the sex organ development,male and female gametes formation,fertilization,endosperm and embryo formation.some 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 innermost layer that attain the level of maximum maturity during pollen-tetrad stage.It is composed of a single layer of cells and is characterised by the presence of dense cytoplasm and prominent nuclei.3.Define Endothecium?A. This is a transverse section of the anther, the part of the stamen that actually produces the pollen grains. As part of pollen development, the cells lining the anther lumen – a layer known as the endothecium – secretes materials that are essential for the proper maturation of the pollen grains.it is the fibrous tissue present in the middle layer of anther.4. What is Microspore ?Ans. Microspore is the pollen grain of seed plant.5. What is Palynology?Ans. Palynology is the study of external morphology of pollen grains and spores .6. What is Megasporangium ? Mention the types.Ans. The formation of four haploid megaspores from megaspore mother cell through meiosis.The types are :1. Linear2. T-shaped3. Inverted T-shaped4. Isobilateral7. Define Monosporic, Bisporic, Tetrasporic.Ans. Monosporic: The embryo sac which is derived from only one of the four megaspore.Bisporic: The functional megaspore is developed from two megasporenuclei.Tetrasporic: All the four nuclei of the take part in the formation of tetrasporic embryo sac. 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 fertilisationsyngamy: 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.
DEAR v. Supriya.NB17,GOOD, NEXT TIME DO WELL
Hi madam thisis my second part of my assignment. 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 fertilisationsyngamy: 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.
Gud morning madam,this is my third part of assignment .Q11.Define ruminent endosperm?Ans. Ruminate endosperm, the condition in which the endosperm is dissected by in-growths of the seed coat. Eg.ArecaceaeQ12.Define helobial endosperm?Ans. This is an intermediate form between the other two types. In this type, Cell wall formation follows the first cell division. But the subsequent divisions do not lead to cell wall formation. Eg. MonocotyledonsQ13. Difference between monocot and dicot embyros?Ans. The main difference between monocot and dicot is that monocot contains a single cotyledon in its embryo whereas dicot contains two cotyledons in its embryo.Monocot leaves show parallel venation and dicot leaves show reticulate venation. Monocot show fibrous root system dicots show tap root system.Q14. Define scutellum?Ans. It is the characterestic features of monocot only.The monocot consists of a large and shield shaped cotyledon known as scutellum.it is involving in absorbing nutrients from the endosperm . its other function is to transferiing it to the growing embryo during seed germination.Q15. Define polyembryony? Ans.The production of two or more embryos in one seed, due either to the existence and fertilization of more than one embryonic sac or to the origination of embryos outside of the embryonic sac. The production of two or more embryos in one seed, due either to the existence and fertilization of more than one embryonic sac or to the origination of embryos outside of the embryonic sac. Q16. What are the objectives of polyembryony?Ans. 1. cleavage of the embryo. 2. formation of embryosacs form other cells of the embryosacs. 3. for the development of one than one embryosac within the same ovule.THANK YOU MAM.