Question

A normal woman, whose father was colour blind is married to a normal man. The sons would be :

• A. $50\%$ colour blind
• B. All normal
• C. All colour blind
• D. $75\%$ colour blind

Answer 1

The correct option is A $50\%$ colour blind

Colour blindness is an X-linked disorder.
All daughter of a colour blind man will be carrier.

If the carrier marries a normal man, then $50\%$ of the sons will be colour blind.