Model Question Paper for M.Sc. (Agri.) Qualifying Examination GPB GKVK

Department of Genetics and Plant Breeding

Agriculture College, UAS GKVK

Model Question Paper for M.Sc. (Agri.) Qualifying Examination
Duration: 3 Hours  Maximum Marks: 100

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I. Define / Answer in Brief (Any 10)

(1 × 10 = 10 marks)

1. Multiple allelism

2. Plant introduction

3. Totipotency

4. Pseudo-dominance

5. Luxuriance

6. Co-dominant markers

7. Dominance hypothesis of heterosis

8. De-animation

9. Joint scaling test

10. Maternal effect

11. Progeny test

12. Permanent translocation heterozygotes

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II. Substantiate the Following (Any 10)

(2 × 10 = 20 marks)

1. Selection is operated after F₅ in bulk method of breeding.

2. Epistatic variance is not fixable.

3. RILs and DH mapping populations are considered as immortal populations.

4. Inbreeding is equally important to exploit heterosis.

5. Johannsen’s pureline theory serves as the basis for the improvement of self-pollinated crops.

6. Single-cross hybrids are more heterotic and commercially acceptable.

7. Standardization of LD₅₀ is a pre-requisite for induction of mutations.

8. Inversions are called as cross-over suppressors.

9. Intercalation prevents faithful replication of DNA.

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

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III. Write Short Notes on the Following (Any 10)

(3 × 10 = 30 marks)

1. Synaptonemal complex (with diagram)

2. Biochemical and physiological basis of heterosis

3. Scaling and joint scaling tests

4. Advantages and disadvantages of first-degree statistics-based genetic analysis of quantitative traits

5. Lampbrush chromosomes

6. Sex-limited, sex-influenced, and sex-linked traits

7. Three-point and two-point test cross in estimating recombination frequencies

8. Accepted model of chromosome structure

9. Diallel selective mating design

10. Multiple factor hypothesis

11. Role of vectors in cloning

12. Synthetics and composites

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IV. Answer the Following with Appropriate Examples (Any 8)

(5 × 8 = 40 marks)

1. Discovery of the white eye mutant in Drosophila by Thomas Hunt Morgan laid the foundation for the development of significant genetic concepts. Substantiate this statement.

2. List the different mechanisms of sex determination and explain how a single gene is able to determine sex in plants with an appropriate example.

3. Considering genes AB–CDEFGH on a pair of chromosomes and if inversion occurs between DEF followed by crossing over in the inversion heterozygote between EF genes, write the gametes formed after meiosis. What are the genetic significance and consequences?

4. Explain Johannsen’s theory of pure line selection and his experiment.

5. Write the procedure of recessive gene transfer through backcross method.

6. Considering two sets of genes — ABC–DEFG and PQR–STUV — on two different pairs of chromosomes, and if crossing over occurs in a translocation heterozygote between EFG and TUV genes, write the gametes formed after meiosis for adjacent and alternate disjunction (with diagrams).

7. Explain briefly about the development of synthetics and composites.

8. What is selection? Briefly explain the types and patterns of selection.

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

10. Derive components of means of P₁, P₂, F₁, F₂, B₁, and B₂ generations assuming adequacy of the additive–dominance model.

11. How does pre-breeding supplement the existing germplasm? What are the limitations of mutations?

12. Explain the inheritance of quantitative traits based on graphical analysis of data from the progeny obtained by diallel mating design.