When a colour blind woman marries a normal man; what is the probability of their son being colour blind?

A. 25%
B. 100%
C. 50%
D. 0%

Correct Answer:

Option B – 100%

Explanation

If a woman is colorblind, that means she has the nonworking gene on both X chromosomes.

Since sons almost always get their only X chromosome from their mom, chances are they will be colorblind too