Recessive sex-linked traits colorblindness PLEASE HELP???

In humans colorblindness is a recessive sex linked trait. What is the probablility that the children of a woman heterozygous for colorblindess and a man with normal vision would be colorblind. Explain





Please help?

Recessive sex-linked traits colorblindness PLEASE HELP???
the phenotypes for this cross would be 50% normal female, 25% normal male, 25% colorblind male.


This is a sex linked trait, which means the gene for it is carried on the X chromosome.


Females have two X chromosomes, and since the father is normal there is no chance of a female being colorblind (she may however, be a carrier)


Males only have one X chromosome, which they recieve from their mother. Since the mother is heterozygous (one dominat and one recessive) there is a 50:50 chance that her son will inherit colorblindness from his mother.





For the phenotypes, if you are using B for dominat(regular) and b for recessive (colorblind), the phenotype ratio would be:


25% X(B)X(b); 25% X(B)X(B); 25% X(B)Y; 25% X(b)Y;





you could use any letter you wanted instead of b, and the b's in parentheisis would be superscripts