NEET 2005
- Exam
- NEET
- Year
- 2005
- Subject
- Zoology
- Chapter
- Principles of Inheritance and Variation
NEET 2005 · Zoology · Principles of Inheritance and Variation
A woman with normal vision, but whose father was colour blind,...
A woman with normal vision, but whose father was colour blind, marries a colour blind man. Suppose that the fourth child of this couple was a boy. This boy:

Options
- Amay be colourblind or may be of normal vision
- Bmust be colour blind
- Cmust have normal colour vision
- Dwill be partially colour blind since he is heterozygous for the colourblind mutant allele.
Correct answer
A. may be colourblind or may be of normal vision
Step-by-step solution
The woman has normal vision but her father was colour blind so she should be the carrier to the disease as Colour blindness is an X-Linked recessive disorder.
The genotype of the woman would be:
The genotype of man to be colour blind should be:


The probability of Male child to be colour blind will and the ratio of diseased to a normal male child is .
The probability of Male child to be colour blind will and the ratio of diseased to a normal male child is .