Mrs. Eryth is carrier of the sex-linked hemophilia allele, and Mr.

Eryth is normal (as far as blood chemistry goes).
A. Draw a Punnet square that shows the theoretical genotypes and
phenotypes among their children.
B. They actually have 4 male and 4 female children; how many of
each sex would be expected to be hemophiliacs, carriers, and
normal?

1 answer

https://en.wikipedia.org/wiki/Punnett_square