Question

How many pairs of chromosomes does a male Drosophila fly have? Which one of these bears the gene for the eye colour?

Answer 1

A male Drosophila fly has four pairs of chromosomes: three pairs are autosomes (II, III, IV) and one pair is sex chromosomes (I). The gene for eye colour is located on the X chromosome, which is part of the sex chromosomes. Thus, the X chromosome bears the gene for eye colour .