Biology by Richa

Biology (XII )

GENETICS

1. (a) How many alleles are involved in the inheritance of blood group in humans?

(b) There is a boy with blood group A, whose mother has blood group B. Give the possible genotype(s) and phenotype(s)

of the father.

2. A woman with blood group O married a man with AB group. Show the possible blood groups of progeny. List the alleles

involved in this inheritance.

3. Why Mendel selected pea plant for genetic research?

4. Why is Mendel considered as the father of Genetics?

5. Give the genotypic and phenotypic ratios of the F1 generation, when a hybrid tall (Tt) pea plant is crossed with pure

dwarf (tt) pea plant.

6. A particular garden pea plant produces only violet flowers.

(a) Is it homozygous dominant for the trait or heterozygous ?

(b) How would you ensure its genotype ? Explain with the help of crosses.

7.(i) Why are grasshopper and Drosophila said to show male heterogamity ? Explain.

(ii) Explain female heterogamity with the help of an example.

8. Explain the sex determination mechanism in humans.How is it different in birds?

9. Briefly describe incomplete dominance with an example.

10. Describe the mechanism of pattern of inheritance of ABO blood groups in humans?

11.(a)Why is haemophilia generally observed in human males?Explain the conditions under which a human female

behaemophillic.

(b) A pregnant human female was advised to undergo M.T.P. It was diagnosed by her doctor that the foetus she is carrying

has developed from a zygote formed by an XX-egg fertilized by Y-carrying sperm.Why was she advised to undergo M.T.P.?

12. Why is haemophilia generally occurs in male not in female?

13. Differentiate b/w

(a) DNA and RNA.

(b) EXON and INTRON

(d) TEMPLATE STRAND and CODING STRAND

14.Why human genome project is called a mega project?

15.HOw is hnRNA converted into mRNA?

RICHA GUPTA

Thursday 3 October 2013