In the fruit fly, Drosophila melanogaster, two different genes control body colour and eye colour. • G/g are alleles of the body colour gene. • G results in grey body, g results in black body. :• R/r are alleles of the eye colour gene. • R results in red eyes, r results in brown eyes. Each gene is autosomal. A dihybrid cross was carried out using a fly with a grey body and red eyes crossed with a fly with a black body and brown eyes. Both parents were homozygous for both genes. The offspring from the F1 generation were crossed to obtain the F2 offspring.