Crossing male fruit fly with female fruit fly(heterozygous,, Homozygous)?

if a white eyed male fruit fly were crossed with a heterozygous red-eyed femal fruit fly, what ratio of genotypes would be expected in the offspring?

Crossing male fruit fly with female fruit fly(heterozygous,, Homozygous)?
I have a different answer. First, the eye color gene is on the X chromosome. Let's call red eyes W and white eyes w because red eyes are dominant (which you can determine because the female is heterozygous for eye color and has red eyes).





So, the male's genotype is wY.


The female's genotype is Ww.





Male progeny can only get a Y chromosome from the male, so they will not inherit any eye color genes from him. Male progeny can only inherit eye color genes from the female, and there are two choices here: W or w.


So, half of the male progeny will be WY (red eyes) and half will be wY (white eyes).





Female progeny have inherited one of their X chromosomes from the male, so they all have at least one w. From the female parent, the female progeny can inherit either W or w. So, half of the female progeny will be Ww (W from female parent and w from male parent = red eyes) and half of the female progeny will be ww (both parents pass on w = white eyes).





In total, half of your male offspring are WY and half are wY. Half of your female offspring are Ww and half are ww. Phenotypically, half of your total offspring are red-eye and half are white-eye.
Reply:Since red eye is dominant, and white eye trait is recessive:





Male genotype: X_w Y


Female genotype: X_r X_w





So:


ALL (100%) males of this union would have white eyes, and half (50%) of the girls would have white eyes, while the other half (50%) of the girls would have red eyes.





--Peace