IGNOU LSE-06 - Developmental Biology

Part-I (Plant Developmental Biology) 1. Define megasporogenesis. Why is it considered important for the sexually reproducing plants? 2. Differentate between gametophytic and sporophytic incompatibility. 3. What is vivipary? How does it help the mangrove species to survive in their saline/estuarine habitat? 4. Define dormancy. What is the importance of seed coat in contracting dormancy? 5. Write short note on the following: a) Parthenocarpy b) Cellular Totipotency c) Senescence of Chloroplasts d) Techniques of Plant Tissue Culture Part-II (Animal Developmental) 6. Describe the following briefly: i) Fate of CFU-M, L stem cells in mammals ii) Test of genomic equivalence iii) Role of morphogenetic field in development of eye iv) Role of prothoracic gland in insect metamorphosis 7. Answer the following briefly: i) List out the different germ layers present in the gastrula. ii) Name the three zones from the outer to the inner side of neural retina. iii) List the secondary egg envelopes in chick. iv) What is blastema? What is its role in the regeneration of the limb in urodele (salamander)? v) How does the Rubella virus infection in a 4-5 weeks pregnant woman affect the unborn baby? 8. Describe the following briefly: i) Allometric and isometric growth ii) Totipotency and pluripotency iii) Holoblastic and meroblastic cleavage iv) Morphollaxis and epimorphosis 9. Explain with neat, labelled diagrams the following: i) Stages in vertebrate spermatogenesis ii) Circulatory system changes during human development from foetal to infant stage iii) Incomplete extensive metamorphosis in dragon files iv) The process of cell death in the control of pattern formation of limbs

Part-I (Plant Developmental Biology)  1. Differentiate between:  (i) Heartwood and sapwood (ii) Composite and ruminate endosperm (iii) Recurrent and non-recurrrent apomixis (iv) Amoeboid and secretory tapetum 2. (a) What is apical dominance? Discuss the role of chemical factors in controlling it. (b) Define polyembryony and describe its various types.  3. Make well labelled diagrams of the following:  (i) Types of ovules (ii) Secondary growth in dicot stem (iii) Syngamy and triple fusion (iv) Structure of periderm 4. (a) What are cambial variants? Describe some of them with examples. (b) Describe the major applications of plant tissue and organ culture. (5) (5)  5. Write short notes on the following:  (i) Cellular totipotency (ii) Commercial cork (iii) Physiological effects of two naturally occurring plant growth regulators (PGRs) (iv) Parthenocarpy  Part-II (Animal Developmental)  6. (a) What are the major differences in the development and differentiation of an egg and a sperm? (b) Define the following terms:  (i) Morphogenetic movements (ii) Epiblast  7. Discuss the differentiation of an erythrocyte from a pluripotent CFU-S cell. 8. Discuss the process of mesoderm induction in amphibian embryos.  9. What is neoteny? Briefly discuss neoteny in different species of urodeles. What is the significance of neoteny in evolutionary process? 10. Write short notes on:  (i) Interstitial cells of Hydra (ii) Neoblasts of Planaria 11. Explain that cancer is a multicausal and multistep process. 12. How is the placenta formed? What are its functions?