GENETICS (Paper-II) Mendelian Genetics and Biometry Question Paper - 2010

II Semester B.Sc. Examination, May/June 2010

(Semester Scheme)

GENETICS (Paper-II) Mendelian Genetics and Biometry

Time: 3 Hours                                                                               Max. Marks : 60

Instruction:  1) Answers Should be written completely only in English. 
                        2) Answer all the Sections.

SECTION - A

Answer any 7 sub-questions. Each sub-question carries 3 marks.                            (5x3=15)

1. a) Explain briefly the theory of Germplasm.
    b) Differentiate Genotype and Phenotype with suitable example.

    c) Write the properties of a normal curve.
    d) What is a test cross? Explain with an example.

    e) Define Phenocopies. Illustrate with suitable example.

    f) A man of blood group AB marries a woman of blood group B(Heterozygous). What will be   blood group of their children?

    g) Explain XX-XO type of sex determination with an example.

   

SECTION - B

Answer any 5 of the following questions. Each question carries 5 marks.                              (5x5=25)

2. Explain incomplete dominance with an example.
3. Give reasons for the success of Mendel's experiments with pea plant.

4. With suitable example illustrate duplicate recessive gene interaction.

5. Define standard deviation. List any two merits and demerits of standard deviation.

6.  What are multiple alleles? Explain with reference to the inheritance of eye colour in Drosophila.

7. Two varieties of Snapdragons are with red flowers and other with white flowers were crossed.
The results obtained in F2 generation are 22 Red, 52 Pink and 23 White flower plants. Ascertain whether these figures show that segregation occurs in the ratio of 1:2:1 (Table value of Chi-square at 5% level of significance is 5.99)

8. Explain the hormonal control of sex determination.

SECTION - C

Answer any 3 of the following questions. Each question carries 15 marks.                              (3x15=45)

10. Explain Bridges genic balance theory of sex determination in Drosophila.

11. Define Epistasis. Explain dominant epistasis with an example.

12. a) Describe the law of Independent Assortment.
b) IN guinea pigs rough coat 'R' is dominant over smooth coat 'r' and black coat colour 'B' over white 'b'. Find the phenotypic and genotypic ratio of the following crosses:
i) RRBb x rrbb
ii) rrBB x rrbb

 13. A husband and wife appear in the interview for two vacancies in the same post. The probability of the husbands selection is 1/7 and the wife is 1/5. What is the probability that? i) Both of them will be selected
ii) Only one of them will be selected
iii)None of them will be selected