Final answer:
In Drosophila, the female is the homogametic sex (XX), while males are heterogametic (XY).
Step-by-step explanation:
In Drosophila melanogaster, commonly known as the fruit fly, sex determination is similar to humans where females have two of the same kind of sex chromosome and are therefore the homogametic sex. This means that female Drosophila have two X chromosomes (XX), making them homogametic (option E). In contrast, Drosophila males are heterogametic with one X and one Y chromosome (XY), and thus they only have one allele for any X-linked characteristic making them hemizygous for those traits. Females can possess homozygous alleles for traits (e.g., XX) or heterozygous alleles (e.g., XwXW for eye color), while the males only have one allele since the Y chromosome does not carry the same genes as the X chromosome.