Red-green color blindness is an X-linked recessive trait in humans. A color-blind woman and a man with normal vision have a son. What is the probability that the son is color-blind?
A) 100 percent
B) 75 percent
C) 50 percent
D) 25 percent
E) 0 percent

Question

Quizplus · Accepted Answer

Since the mother is color-blind (homozygous recessive) and the father has normal vision (hemizygous dominant), the son will inherit the X chromosome carrying the color-blind allele from his mother and the Y chromosome from his father, resulting in a 100% probability of being color-blind.

Red-Green Color Blindness Is an X-Linked Recessive Trait in Humans