Red-green color blindness is a sex-linked recessive trait in humans. Two people with normal color vision have a color-blind son. What are the genotypes of the parents?
A) XNXn and XnY
B) XnXn and XNY
C) XNXN and XnY
D) XNXN and XNY
E) XNXn and XNY

Question

Quizplus · Accepted Answer

The mother must be a carrier (XNXn) to pass the recessive allele to the son, and the father must have normal vision (XNY).

Red-Green Color Blindness Is a Sex-Linked Recessive Trait in Humans