Final answer:
In Drosophila, the gene for red eyes (R) is dominant to the allele for white eyes (r). This gene is sex-linked and located on the X chromosome. A cross between a homozygous red-eyed female and a white-eyed male will result in all red-eyed offspring in the F1 generation. A subsequent cross between F1 offspring will produce both red-eyed and white-eyed females, and only white-eyed males in the F2 generation.
Step-by-step explanation:
In Drosophila, the gene for red eyes, R, is dominant to the allele for white eyes, r. This gene is located on the X chromosome, making it sex-linked. When a homozygous red-eyed female (XWXW) is crossed with a white-eyed male (XWY), all the offspring in the F1 generation will have red eyes. The females in the F1 generation will be heterozygous (XWXw) for the eye color gene, while the males will be hemizygous (XWY).
If a cross is then made between an F1 female (XWXw) and an F1 male (XWY), the F2 generation will have both red-eyed and white-eyed females, and only white-eyed males. The expected genotype ratio in the F2 generation will be 1:1 for red-eyed females (XWXw : XWXW) and 1:1 for white-eyed females (XWXw : XwXw), and the phenotype ratio will also be 1:1 for red-eyed females to white-eyed females.
On the other hand, the expected genotype ratio in the F2 generation for red-eyed males (XWY) to white-eyed males (XwY) will be 1:1, while the phenotype ratio will be 1:1 for white-eyed males to red-eyed males.