JIPMER2007ZoologyPrinciples of Inheritance and Variation
A woman with normal vision, but whose father was colourblind, marries a colourblind man. Suppose that the fourth child of this couple was a boy. This boy
Options
- Amust have normal colour vision
- Bwill be partially colourblind since he is heterozygous for the colourblind mutant allele
- Cmust be colourblind
- Dmay be colourblind or may be of normal vision
Correct answer
D. may be colourblind or may be of normal vision
Step-by-step solution
Colourblindness is a sex linked (X-linked) trait. It always transfers from mother to son. A woman, whose father was colourblind, will cross be carrier for colourblind trait. Marriage of this woman with a colourblind man will result of the following possibilities.