[Campbell Biology P.348] A father has red-green color blindness, an X-linked recessive trait... | Practice Question

A father has red-green color blindness, an X-linked recessive trait. He has a child with a woman who is homozygous for normal color vision. Which of the following is true about their offspring?

  • A: All sons will be color-blind, and all daughters will have normal vision.
  • B: All daughters will be carriers, and all sons will have normal vision.
  • C: There is a 50% chance that each son will be color-blind.
  • D: All children, regardless of sex, will be carriers of the trait.

Explanation

This scenario matches Figure 15.7a. The father's genotype is XnY and the mother's is XNXN. All daughters will inherit XN from the mother and Xn from the father, making them genotype XNXn carriers with normal vision . All sons will inherit XN from the mother and Y from the father, making them genotype XNY normal vision .