Question

Consider a cross between a homozygous white-eyed female Drosophila and a red-eyed male Drosophila. What proportion of the female offspring would be expected to be white-eyed? What proportion of the male offspring would be expected to be white-eyed?

Answer 1

In a cross between a homozygous white-eyed female Drosophila and a red-eyed male Drosophila, all the female offspring would be expected to be white-eyed.

Step-by-step explanation:

In a cross between a homozygous white-eyed female Drosophila and a red-eyed male Drosophila, the proportion of female offspring expected to be white-eyed is 100%. This is because the gene for eye color is carried on the X chromosome, and the male offspring receive their X chromosome from the white-eyed female, resulting in white-eyed males. On the other hand, the female offspring receive one X chromosome from the white-eyed female and one X chromosome from the red-eyed male, making them heterozygous carriers of the white-eye gene, but without expressing it.