A color blind man marries a woman with normal vision. The women's father is also

[Jessica]

color blinds...? A color blind man marries a woman with normal vision. The woman's father is also color blind. If they have four children, what is the chance that two will be color-blind sons? will it be 1/4 X 1/4 X 1/4 X 1/4? or is it something else because it is two sons?

[cynedyr]

* X 1/2 X * X 1/2 The chance of a son getting a colorblind allele from the father is 0%, they get the Y. The chance of getting a colorblind allele from the mother is 50% (Her father passed his colorblind + X to his daughter). Each son has a 1/2 chance of being colorblind. When considering the probability of both events occuring that is 1/2 X 1/2 = 1/4. So there's a 1/4 chance of both sons being colorblind.