LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034
B.Sc. DEGREE EXAMINATION – PLANT BIOLOGY & PLANT BIO-TECH.
FIFTH SEMESTER – APRIL 2012
PB 5516/PB 5510 - GENETICS, PLANT BREEDING AND EVOLUTION
Date : 27-04-2012
Time : 9:00 - 12:00
Dept. No.
Max. : 100 Marks
PART-A
Answer the following, each within 50 words:
(10 x 2 =20marks)
1. Incomplete dominance
2. Test cross
3. Cistron
4. Transposable elements
5. Chemical mutagens
6. 21 trisomy
7. Centres of origin
8. Heterosis
9. Speciation
10. Neo Lamarckism
PART-B
Answer the following, each within 500 words, draw diagrams wherever necessary:
(5x7=35 marks)
11. a) Explain multiple alleles with one example.
(OR)
b) Give an account of quantitative inheritance.
12. a) Explain genetic code.
(OR)
b) Explain genetic recombination using neurospora tetrad formation.
13. a) Write about chromosomal abbreations.
(OR)
b) Distinguish between auto and allopolypoidy.
14. a) Give an account on types of selection.
(OR)
b) Discuss the origin of cultivated plants.
15. a) Write a note on origin of species.
(OR)
b) Explain Lamarckism and its role in evolution.
PART-C
Answer any Three of the following, each within 1200 words only;
Draw diagrams and flowchart wherever necessary:
16. Describe sex determination in plants.
17. Discuss the gene regulation in prokaryote.
18. Explain the steps involved in hybridization.
19. Write a detailed account of DNA repair mechanism.
20. Explain natural selection and its role in evolution.
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(3x15=45)