A colorblind man marries a woman who is heterozygous for the trait. What proportion of their sons, if they have any, can be expected to be colorblind?
A) 1:2
B) 1:4
C) 1:8
D) All their boys will be colorblind.
E) 0

Question

Quizplus · Accepted Answer

Colorblindness is a sex-linked recessive trait. The woman is heterozygous (X^NX^n), and the man is colorblind (X^nY). Sons inherit their X chromosome from their mother, so there is a 50% chance (1:2) that a son will inherit the X^n (colorblind) allele from her.

A Colorblind Man Marries a Woman Who Is Heterozygous for the Trait