34.When Thomas Hunt Morgan crossed his red-eyed Fi generation flies to each other, the F2 generation included both red- and white-eyed flies. Remarkably, all the white-eyed flies were male. He concluded that the involved gene was on the X chromosome. Why he could make this conclusion?
(A)Before this experiment, he already knew the genes are located at chromosome.
(B)Before this experiment, he knew that the sex was determined by X and Y chromosome.
(C)He knew the phenotype of eyes was sex-Iinkage.
(D)His conclusion makes non-sense at all.
(E)Before this experiment, he knew that Y-chromosome canys very few genes.