GENETICS Question Papers (Supple, November 2007, RR)

SET :1
1. Discuss Mendel’s postulates based on his monohybrid cross results. [4+12]

2. What is the difference in genetic material distribution in prokaryotic and eukaryotic cells. Explain it’s consequences. [8+8]

3. Why does more crossing occur between two distant linked genes than between two genes that are very close together on the same chromosome? [8+8]

4. Describe how transformation is useful in genetic engineering. [4+12]

5. What are translocations? How do they affect the genetic material? Elucidate your answer with suitable examples. [4+12]

6. Differentiate between point mutations that re transitions versus tranversions. Using the DNA bases (A, T, G and C) list the four types of transition and the eight types of transversions. [5+11]

7. What is difference between X and Y chromosomes? Explain with examples. [8+8]

8. What is kappa in Paramecium? [4+12]


SET :2

1. What properties of Fruit Flies and made them the organism of choice for genetics? [5+11]

2. Write an essay on the higher order chromatin organization. [6+10]

3. Describe the experiment of Creighton and McClintock that demonstrated that recombination involved a physical exchange of chromosomal material? [8+8]

4. Write a note on Virus -mediated bacterial DNA transfer. [4+12]

5. Write the function and organization of nucleosome. [4+12]

6. What is difference between a chromosomal aberration and gene mutation? [8+8]

7. Relate the potential effect of the Lyon hypothesis on the retina of a human female heterozygous for the X-linked red-green color-blindness. [8+8]

8. How would you determine that a segregative petite mutant in yeast is controlled by a chromosomal gene? [4+12]


SET :3

1. Consider the F2 offspring of Mendel’s dihybrid cross. Determine the conditional probability that F2 plants expressing both dominant traits are heterozygous at both loci. [4+12]

2. What is the output of Avery and his colleague’s experiment on transforming ability of the DNA? [6+10]

3. Explain the experimental proof which forms the cytological basis of crossing over. [8+8]

4. How is mapping done by tetrad analysis? [8+8]

5. Write a note on structure and organization of Lampbrush chromosomes. [4+12]

6. Write an essay that describes mutations. [3+13]

7. Contrast the fertility of an allotetraploid with an autotriploid and an autotetraploid. [8+8]

8. What is kappa in Paramecium? [4+12]


SET :4

1. What type of crosses would produce the following genetic ratios?
(a) 3:1
(b) 1:1
(c) 1:2:1
(d) 9:3:3:1 [4×4]

2. Elaborate on the various contributions made in understanding transformation by Griffith, Avery and his co-workers. [4+12]

3. Write a note on map-distances. [6+10]

4. Describe the mode of conjugation and transformation in detail. [8+8]

5. Explain the terms
(a) Histones and Non-histones
(b) Chromosome scaffolds. [8+8]

6. 5-bromouracil, 2-aminopurine, proflavin, ethylethane sulfonate and nitrous acid are chemical mutagens. What does each do? [16]

7. Contrast the fertility of an allotetraploid with an autotriploid and an autotetraploid. [8+8]

8. How would you determine that a segregative petite mutant in yeast is controlled by a chromosomal gene? [4+12]