Question

A woman who is colorblind who also has a colorblind daughter is suing a normal vision man for paternity. You have been called into court as an expert in genetics to testify. What do you tell the jury? Fully explain your answer. Do not just say he is or isn’t the father.

Answer 1

Ans) It should be noted that color blindness is X-linked recessive genetic disorder. Let the genotype of Colorblind women be XaXa and Normal vision man be XAY. After cross we get, all daughters with normal vision and all son affected.This clearly indicates that the Man is not a father of the daughter of the woman who is suing.

If the father is also color blind,then only daughter will be colourblind (since it as autosomal recessive condition and female is already homozyogous recessive.If the father will be Dominant or normal then progeny will always receive one Dominant allele from the father and she will be normal).Thus,the father should be affected or colorblind.