White eyes are a recessive sex-linked trait in Drosophila.If a white-eyed female fly is mated to a red-eyed male, their offspring should be
A) 50 percent red-eyed and 50 percent white-eyed for both sexes.
B) all white-eyed for both sexes.
C) all white-eyed males and all red-eyed females.
D) all white-eyed females and all red-eyed males.
E) males that are 50 percent red-eyed and 50 percent white-eyed, and females that are all red-eyed.

Question

Quizplus · Accepted Answer

Since white eyes are a recessive sex-linked trait located on the X chromosome, and the female fly has two X chromosomes with the white-eyed allele (being homozygous recessive), all her male offspring will inherit her X chromosome with the white-eyed allele. The male offspring inherit their Y chromosome from their father, which does not carry an allele for eye color. The female offspring will inherit one X chromosome with the white-eyed allele from their mother and one X chromosome with the red-eyed allele from their father, displaying the dominant red-eyed phenotype.

White Eyes Are a Recessive Sex-Linked Trait in Drosophila