If a man has red-green color blindness, a sex linked dominant trait, what is a possible genotype of his father? I. XR Y II. Xr Y III. XR XR IV XR Xr A. Only III B. I and III C. I and II D. I, III, and IV

C

Explanation:

The possible genotype of his father is and .

For sex-linked traits, an affected man always inherit the affected allele from the mother. The other chromosome, which is the Y chromosome is always from the father and this confers maleness on individuals.

The father of a man affected for a sex-linked trait can be affected for the same trait or otherwise. It does not have any bearing on the male child since the father only donates the Y chromosome to the male child.

Hence, in this case, the father can either be affected for the same trait () or be free from it ().

The correct option is C.