Final answer:
The orange eyes in the fruit fly cross are recessive to black eyes. A cross between a white-eyed male and a heterozygous red-eyed female results in a 1:1 ratio of red to white-eyed offspring for both sexes.
Step-by-step explanation:
The result of the cross indicates that orange eyes are recessive to black eyes. In Drosophila (fruit flies), eye color is often used as an example of a sex-linked trait. In a cross between a homozygous red-eyed female fruit fly and a white-eyed male fruit fly, the expected outcome for the F1 generation would be all red-eyed offspring since red is dominant over white.
However, a cross between a white-eyed male (XY) and a female heterozygous for red eye color (XwXw) would result in different phenotypes for the different sexes: 50% of the female offspring would be heterozygous with red eyes, 50% of the female offspring would be homozygous with white eyes, 50% of the male offspring would have red eyes (hemizygous dominant), and 50% would have white eyes (hemizygous recessive), giving a 1:1 ratio of red to white eyes for both sexes.