Question

I need help pls...

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

Answer 1

C

Step-by-step explanation:

The possible genotype of his father is
`X^RY` and
`X^rY`.

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 (
`X^RY`) or be free from it (
`X^rY`).

The correct option is C.