Color blindness is a recessive sex-linked trait. If a man with normal color vision and a woman who is a carrier for the color blindness trait have a son, what is the probability that he will be color-blind?

Question

Quizplus · Accepted Answer

Since color blindness is a sex-linked trait located on the X chromosome, and the mother is a carrier (XcX), she can pass either the X chromosome with the color blindness gene (Xc) or the normal X chromosome (X) to her son. The father, with normal color vision (XY), can only pass the Y chromosome to his son. Therefore, there is a 50% chance the son will inherit the Xc from his mother and be color-blind.

Color Blindness Is a Recessive Sex-Linked Trait