LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

ED 08

B.Sc. DEGREE EXAMINATION – PLANT BIOLOGY & PLANT BIO-TECH.

FIFTH SEMESTER – November 2008

PB 5510 – GENETICS PLANT BREEDING & EVOLUTION

 

 

 

Date : 05-11-08                     Dept. No.                                        Max. : 100 Marks

Time : 9:00 – 12:00

PART – A

1. Choose the correct answer.

(5 x 1 = 5)

1. Transformation experiment gave a proof of the fact that
2. Bacteria reproduce sexually b) RNA is the genetic material  c) DNA is the genetic material         d) Chromosomes are made of DNA
3. A micromutation is
4. Change in gene b) addition of chromosome     c) delition of chromosome      d) monoploidy
5. The theory of iheritance of acquired characters was proposed by
6. Darwin b) Lamarck      c) Weismann               d) Mendel
7. One of the following organellels is related with genetic engineering
8. Plastids b) mitochondria           c) Golgi apparatus       d) Plasmids
9. The following does not play and part in evolution
10. Mutation b) polyploidy               c) acquired characters             d) natural selection

 

1. State Whether the following statements are true or false

(5 x 1 = 5)

6. In E.coli Lac operon is induced by lactose
7. A cross of the F₁ with the recessive parent is known as back cross
8. Neurospora is suitable for genetic studies because it has very short life.
9. The term pureline was introduced by Wallace.
10. Inorganic evolution explains the changes that are taking place in nonliving objects.

 

III        Complete the following.

(5 x 1 = 5)

11. A complete set of chromosomes inherited as a unit from one parent is called __________.
12. Hereditary variations in plant can be produced by ________________
13. The genotype of the F₂ heterozygous tall is __________________
14. Emasculation is achieved by the removal of ________________
15. ‘Origin of species’ was written by ______________

 

1. Answer all questions, each within 50 words.

(5 x 1 = 5)

16. What is incomplete dominance?
17. Define cistron
18. What is Down’s syndrome?
19. Write short notes on point mutation.
20. Define heterosis

 

 

PART – B                                          (5 x 8 = 40)

 

Answer any FIVE, each within 350 words. Draw diagrams wherever necessary:

 

21. Give an account of post transcriptional modifications.
22. Explain briefly about cytoplasmic inheritance with suitable example.
23. Write notes on the objectives of Plant breeding
24. Describe the mass selection.
25. Write notes on chemical mutagens
26. Discuss about the sex determination in plants.
27. Write short notes on Hybridization techniques.
28. Briefly explain the principles of Lamarckism.

 

PART – C                                          (2 x 20 = 40)

 

Answer the following, each within 1500 words. Draw diagrams wherever necessary:

 

29. a) Give an account on Polyploidy. Add a note on its significance.

(or)

1. Write an essay on different types of chromosomal aberrations.

 

30. a) Give a detailed account of DNA repair mechanisms

(or)

1. Write notes on:

• Multiple alleles
• Lethal genes
• Transposable elements

 

 

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