M.Sc. (Agri.) Written Qualifying Examination – 2014–15 (UAS, GKVK)

Department of Genetics and Plant Breeding

College of Agriculture, UAS GKVK

M.Sc. (Agri.) Written Qualifying Examination – 2014–15
Model Question Paper

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I. Define / Explain the following

(1 × 10 = 10 marks)

1. X-linked inheritance

2. Second order segregation

3. Define breeding value in terms of average effects of genes

4. Define average effect of a gene

5. Monosomics

6. Androgenesis

7. Chiasma

8. Self incompatibility

9. RILs

10. Pure line selection

11. Physical mutagens

12. Qualitative traits

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II. Substantiate the following

(2 × 10 = 20 marks)

1. Three-point test cross process is efficient in determining relatively precise map distances.

2. Thomas Hunt Morgan’s discovery of mutant white eye in Drosophila had to be supported with Calvin Bridges’ efforts to prove the physical basis of inheritance.

3. Write the structure of ANOVA for combining ability of Line × Tester mating design.

4. Epistatic variance is not fixable.

5. There will be no faithful replication of DNA due to intercalation.

6. Key features of meiosis that contribute to genetic variations.

7. Cross over helps in creation of variability.

8. Selection in M₁ is not feasible.

9. Inheritance of X-linked traits provides evidence of physical basis of heredity.

10. Selection is not effective in pure lines.

11. Prebreeding is important in crop breeding programme.

12. Marker assisted backcross breeding is more useful in transfer of recessive genes.

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III. Write short notes on the following

(3 × 10 = 30 marks)

1. Complete dominance and no dominance

2. Maternal effect and maternal inheritance

3. Explain the method of estimating additive and dominance genetic variance using variances of basic generations: parents (P₁ & P₂), F₁ (P₁ × P₂), F₂(F₁ × F₁), B₁ (F₁ × P₁) and B₂ (F₁ × P₂).

4. Explain the relative advantages and disadvantages of first-degree statistics-based genetic analysis of quantitative traits.

5. What is C banding? Explain.

6. What is apomixis? Explain its importance in plant breeding.

7. Explain participatory plant breeding.

8. Backcross breeding for recessive traits.

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IV. Answer the following

(5 × 8 = 40 marks)

1. Explain cytological evidence to demonstrate that the F₁ plant heterozygous for two pairs of alleles will produce four types of gametes in equal frequencies.

2. Explain how inheritance of leaf variegation is different from inheritance of traits governed by nuclear genes.

3. Derive the expression for relationship between population mean and gene frequency.

4. Derive components of means of six basic generations when additive-dominance model is inadequate.

5. Write on different physical mutagens used along with their merits and demerits.

6. What are the important steps involved in the development of hybrids? How are the newly developed inbreds evaluated for combining ability?

7. Illustrate the procedure for reciprocal recurrent selection.

8. Differentiate between maternal effect and maternal inheritance with a classical example.

9. Briefly explain the evolution of tetraploid Brassica species.

10. Explain with diagram meiosis-I taking 2n = 4.

11. Explain briefly the utilization of male sterility in plant breeding.

12. What is gene interaction? Explain complementary gene interaction with example.

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V. Write short notes on any FIVE of the following

(5 × 8 = 40 marks)

9. Development of RILs

10. Explain the biochemical basis of heterosis

11. What is marker-assisted selection? Write its principles.

12. Recurrent selection method of breeding

13. Gene action and its implication in cross- and self-pollinated crops

14. Limitations of mutations

15. Inversions are also called as cross-over suppressors