CHAPTER 27: PRINCIPLES OF INHERITANCE AND VARIATION

A tall true breeding garden pea plant is crossed with a dwarf true breeding garden pea plant. When the F 1 plants were selfed the resulting genotypes were in the ratio of

Which one of the following conditions though harmful in itself, is also potential saviour from a mosquito borne infectious disease ?

The mechanism that causes a gene to move from one linkage group to another is called

Pick out the correct statements.

(1)Haemophilia is a sexlinked Recessive disease.

(2)Down’s syndrome is due to aneuploidy.

(3)Phenylketonuria is an autosomal recessive gene disorder.

(4)Sickle cell anaemia is an Xlinked Recessive gene disorder.

Gene which suppresses other gene’s activity but does not lie on the same locus is called as

Thalassemia and sickle cell anaemia are caused due to a problem in globin molecule synthesis. Select the correct statement.

The genotypes of a husband and wife are I ^A I ^B and I ^A i. Among the blood types of their children, how many different genotypes and phenotypes are possible?

In man, which of the following genotypes and phenotypes may be the correct result of aneuploidy in sex chromosomes

Mendel’s rules do not correctly predict patterns of inheritance for tightly linked genes or the inheritance of alleles that show incomplete dominance or epistasis. Does this mean that his hypothesis are incorrect ?

Mendel did not include in his laws

Colour blindness is found more in males than in females because

Male XX and female XY sometime occur due to