Suppose that you examine a vial of 100 flies that are all offspring from a single genetic cross. Also suppose that you find both red-eyed females and white-eyed females, as well as both red-eyed males and white-eyed males. The allele for red eye colour (X^w+) is dominant over the allele for white eye colour (X^w). Which of the following describes the genotypes of the parents?

Question

Quizplus · Accepted Answer

Since both red-eyed and white-eyed offspring are present in both males and females, one parent must be heterozygous for the red eye color allele (carrying both the dominant and recessive alleles), and the other parent must be a male carrying the recessive white eye color allele on his X chromosome and having a Y chromosome without the eye color allele. This scenario is only described in option B.

Suppose That You Examine a Vial of 100 Flies That