biology punnett

Question

3a) Red eyes are dominant on fruit flies but an x-linked recessive allele will produce white eyed flies. If a red eyed female mates with a white eyed male, what is the probability of white eyes in the F1 generation?

3b) Is it possible for a white eyed female to have a white eyed female parent? If so, what must be the male parent’s genotype?

do it by hands

Answer 1

A normal female has XRXR having red eyes and a male having XrY with white eye.All daughters are Red-eye heterozygous and all sons are red-eye homozygous. There will be no white-eyes in F1 generation.

For the female to be white eye she must be homozygous recessive,XrXr.For there to be white eyed females the male parents genotype must be homozygous recessive XrY. It is possible for a white eye female to have a white eyed female parent.