Genetics problem: Mom is a carrier of red-green color blindness and Dad is red-green color-blind. What is the chance that their son will be color-blind?
A)0%
B)50%
C)75%
D)100%

Question

Quizplus · Accepted Answer

Since the father is red-green color-blind, he must have the X-linked recessive gene for color blindness. The mother is a carrier, which means she has one normal X chromosome and one with the color blindness gene. When they have a son, he will inherit one X chromosome from his mother and one Y chromosome from his father.

Therefore, the chance of the son inheriting the X chromosome with the color blindness gene is 50%. This will result in the son being red-green color-blind.

Genetics Problem: Mom Is a Carrier of Red-Green Color Blindness