[Campbell Biology P.349] A white-eyed female Drosophila is mated with a red-eyed wild-type m... | Practice Question

A white-eyed female Drosophila is mated with a red-eyed wild-type male. What are the expected phenotypes of their offspring?

  • A: All offspring will have red eyes.
  • B: All offspring will have white eyes.
  • C: All females will have red eyes, and all males will have white eyes.
  • D: All females will have white eyes, and all males will have red eyes.

Explanation

This is the reciprocal cross to Morgan's original experiment. The female's genotype is XwXw and the male's is Xw+Y. All daughters inherit one Xw from their mother and the Xw+ from their father, making them Xw+Xw red-eyed carriers . All sons inherit one Xw from their mother and the Y from their father, making them XwY white-eyed .