Question

A white-eyed female Drosophila was mated with a red-eyed male. What will be the phenotypes of the male and female progeny?

Answer 1

When a white-eyed female Drosophila (X^w X^w) is mated with a red-eyed male (X⁺ Y), the F₁ progeny will have red-eyed females (X⁺ X^w) and white-eyed males (X^w Y). This is because the red eye color (X⁺) is dominant over white (X^w), and males inherit their single X chromosome from their mother, so they express the white-eye trait if they receive the X^w. Females are red-eyed as they have one dominant X⁺ from the father. Thus, females are red-eyed, and males are white-eyed in F₁ progeny.