GPB 508 Mutagenesis and mutation breeding (2+1) Question Paper

 UNIVERSITY OF AGRICULTURAL SCIENCES, BANGALORE

Department of Genetics and Plant Breeding,
College of Agriculture, GKVK, Bengaluru - 560 065
GPB 508 Mutagenesis and mutation breeding (2+1)

Name: ___________________________________________ Duration: 45 mins

ID No : __________________________________________ Date: 24-02-2026

                                                              Max Marks: 20.00  

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I. Multiple Choice Questions: (0.5x10=5)

1. Who coined the term "Mutation"?

   a. Gregor Mendel b. Hugo de Vries

   c. T.H. Morgan d. Watson and Crick

2. A mutation that involves a change in a single base pair is called:

   a. Chromosomal aberration b. Point mutation

   c. Somatic mutation d. Polyploidy

3. Transitions and transversions are types of:

   a. Frame-shift mutations b. Base substitutions

   c. Deletions d. Inversions

4. Which of the following is a physical mutagen?

   a. 5-Bromouracil b. Nitrous acid

   c. X-rays d. EMS

5. The most common tautomeric form of Guanine is:

   a. Enol b. Keto

   c. Imino d. Amino

6. Which mutagen acts as a base analogue?

   a. UV rays b. 5-Bromouracil

   c. Mustard gas d. Proflavin

7. UV radiation causes mutation primarily by forming:

   a. Double-strand breaks b. Thymine dimers

   c. Deamination d. Alkylation

8. Photoreactivation repair is used to fix damage caused by:

   a. X-rays b. Chemicals

   c. UV Light d. Heat

9. In a DNA strand, nucleotides are linked by:

   a. Hydrogen bonds b. Phosphodiester bonds

   c. Peptide bonds d. Glycosidic bonds

10. A mutation that results in the same amino acid being coded is called:

    a. Missense b. Nonsense

    c. Silent d. Frame-shift

II. Match the Following : (0.5X5=2.5)

1. DNA Ligase A. Removes RNA primers

2. Thymine Dimer B. Joins DNA fragments

3. DNA Pol I C. UV damage

4. Stadler D. Mustard gas

5. Auerbach and robson E. X-rays

Write the Answers: ________________________________

III. True or False : (0.5X5=2.5)

1. Adenine pairs with Cytosine with two hydrogen bonds.

2. Ionizing radiations like Gamma rays are more energetic than UV rays.

3. Excision repair involves the removal of damaged DNA segments.

4. DNA replication is continuous on both strands.

5. A transition mutation is the replacement of a purine by a pyrimidine.

IV. Answer the following

1. Write the classification of mutation - 4marks

2. Factors affecting the mutation - 3marks

3. Briefly explain the DNA repair mechanisms with diagram - 3marks