Cinnabar eyes is a sex-linked, recessive characteristic in fruit flies. If a female having cinnabar eyes is crossed with a wild-type male, what percentage of the F1 males will have cinnabar eyes?

Question

Quizplus · Accepted Answer

Since cinnabar eyes is a sex-linked, recessive trait, and the female (XX) has cinnabar eyes, she must have two copies of the recessive allele. The wild-type male (XY) will contribute a Y chromosome to male offspring, which does not carry the allele for eye color. Therefore, all male offspring (XY) will inherit the X chromosome with the recessive allele for cinnabar eyes from their mother, resulting in 100 percent of the F1 males having cinnabar eyes.

Cinnabar Eyes Is a Sex-Linked, Recessive Characteristic in Fruit Flies