Wild type fruit flies have red eyes. A white-eyed female fly is crossed with a red-eyed male fly. All of the females from the cross are red-eyed and all of the males, white-eyed. What type of inheritance pattern is this?

Question

Quizplus · Accepted Answer

This is an example of sex-linked inheritance on the X chromosome, where the white-eye phenotype is a recessive trait carried on the X chromosome. The male flies only possess one X chromosome, so if the X chromosome carries the white-eye gene, they will exhibit the trait. Females, on the other hand, have two X chromosomes and must have two copies of the white-eye gene to express the trait, which is much less likely.

Wild Type Fruit Flies Have Red Eyes