When Thomas Hunt Morgan Crossed His Red-Eyed F₁ Generation Flies

Multiple Choice

When Thomas Hunt Morgan crossed his red-eyed F₁ generation flies to each other, the ?F₂ generation included both red- and white-eyed flies. Remarkably, all the white-eyed flies were male. What was the explanation for this result?

A) The gene involved is on the Y chromosome.
B) The gene involved is on the X chromosome.
C) The gene involved is on an autosome, but only in males.
D) Other male-specific factors influence eye colour in flies.
E) Other female-specific factors influence eye colour in flies.