Aman with normal color vision married a woman with normal color vision whose father was colorblind, what is the probability of a child with colorblindness?

1/4

Explanation:

Color blindness is a X-linked, recessive trait. Let the allele be represented by c.

Normal color vision man =

Color blind man    =

Normal color vision woman =

Color blind woman =

Since the woman's father is color blind, the woman is a carrier because she must have inherited the allele from the father.

Hence,

  x  

Progeny =

Probability of them having a colorblind child is 1/4.