MAHATMA GANDHI UNIVERSITY, KOTTAYAM, KERALA, INDIA
M.Sc. BOTANY DEGREE EXAMINATION, JULY 2003
Second Semester
Faculty of Sciences, Branch VI – Botany
PAPER – VI – CELL BIOLOGY, GENETICS AND PLANT BREEDING
Time: Three Hours Maximum: 75 Marks
Section A (Cell Biology)
I. Answer any seven of the following: (7 X 1 = 7 Marks)
1. Plasmodesmata
2. Polysomes
3. F0-F1 particles
4. Plastome
5. Ph-chromosome
6. G-banding
7. Chromosome library
8. Balbiani ring
9. Chondrome
II. Answer any two of the following: (2 X 4 = 8 Marks)
10. Describe the ultra-structure of spindle apparatus and synaptonemal complex
11. Explain the biological, physiological and chromosomal effects of radiations.
12. Discuss the unit membrane model of plasma membrane.
III. Answer any one of the following: (1 X 8 = 8 Marks)
13. Give a detailed account of giant chromosomes. Mention their significance.
14. Describe the various numerical and structural variations of chromosomes. Explain their meiotic behavior.
Section B (Genetics)
IV. Answer any five of the following: (5 X 1 = 5 Marks)
15. Write notes on Micro-satellites
16. Comment on Apoptosis.
17. Give an account on Cot-curve.
18. Write notes on Selfish genes.
19. Give an account on Penetrance.
20. What is Wobble hypothesis?
V. Answer any three of the following: (3 X 2 = 6 Marks)
21. Give a brief account of protein targeting.
22. Distinguish between complete linkage and incomplete linkage.
23. Compare transposons and retroposons.
24. Write notes on different RNA forms.
VI. Answer any three of the following: (3 X 4 = 12 Marks)
25. Describe the hardy-Weinberg equilibrium principle. What are its applications?
26. Explain the principle, methods and applications of DNA finger printing.
27. Give a detailed account on the different forms of DNA.
28. Explain briefly the mechanism of sex determination plants.
VII. Answer any two of the following: (2 X 7 = 14 Marks)
29. Compare and contrast the DNA replication mechanism in prokaryotes and eukaryotes.
30. “Transgenesis involves genetic transformation by non-sexual means”-evaluate.
31. Explain the different mechanisms of DNA repair.
Section C (Plant Breeding)
VIII. Answer any four of the following: (4 X 2 = 8 Marks)
32. Distinguish between heterosis and heterobeltiosis.
33. Comment on GM crops
34. Comment on the uses of inter-specific and inter generic hybridization.
35. Differentiate oligogenic mutations from polygenic mutations.
36. How can you induce male sterility? Mention its applications.
IX. Answer any one of the following: (1 X 7 = 7 Marks)
37. Give a detailed account on the role of induced mutations in crop improvement
38. Briefly discuss the concept of centers of origin of species. How is this information useful in Plant Breeding?
