LSE-06 Solved Assignment For IGNOU BSC 2018
Course Title: Developmental Biology
Valid till: 31st December 2018
PART I (Plant Development)
- Make neat and labelled diagrams of the following:
i) Development of monosporic, bisporic, and tetrasporic embryo sacs,
ii) Development of pollen wall,
iii) Endosperm with micropylar haustorium, and
iv) T.s. stem of Bignonia sp.
Write short notes on the following:
i) Types of fruits,
ii) Synergistic and sequential effects of hormones,
iii) Applications of apical dominance in horticulture and agriculture, and
iv) Clonal propagation.
With the help of a flow chart explain the processes involved in the initiation of flower primordia.
PART II (Animal Development)
Explain the results and reasons of the following experiments.
i) When Hydra is transversely sliced into annular segments.
ii) The scientist Mc Kinnel (1962) in his experiments transplanted the blastula nuclei into enucleated eggs.
iii) Spemann and his coworkers grafted a piece of prospective neural ectoderm from an early gastrula stage donor embryo in newt of genus Triturus into a region of host embryo where belly skin should develop.
iv) In chick embryo, a piece of thigh mesoderm is transplanted under the wing ectoderm.
- i) Describe the role of nerves in amphibian regeneration
ii) Describe the stages of pre-embryonic development in humans.
iii) Differentiate between allometric and isometric growth.
iv) Define the term cleavage. Name and describe the types of eggs on the basis of presence of yolk.
- i) What is the significance of gametogenesis process?
ii) Compare the process of oogenesis with spermiogenesis.
iii) With the help of labelled diagrams describe the stages in the acrosome reaction in a mammalian sperm.
- In not more than 500 words:
i) Discuss the contribution of thyroid gland in the process of amphibian metamorphosis.
ii) Outline the stages of carcinogenesis.
With the help of suitable diagrams describe the process of neurulation in frog. How does it differ from neurulation in chick?