Red eyes (e) in fruit flies are recessive to black eyes (E). If a fruit fly physically expresses red eyes, what is its genotype?

Answer: The genotype of a fruit fly which physically expresses red eye is (ee)

Explanation: The red eyes trait (e) is recessive to black eyes (E) that is, the black eyes trait (E) is dominant over the red eyes trait (e). Therefore, for the red eyes trait to manifest physically the genotype must appear as a homozygous allele (ee)