• (a) In Drosophila melanogaster (fruit fly) the gene for eye color is sex-linked on the X chromosome. The gene for the red eye is dominant. A cross was made between a homozygous red-eyed female and a white-eyed male. Work out the genotypes of their offspring.

(a) Give two reasons why the fruit fly is successfully used in genetic study. (2 marks)

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(b) In a population, there are more males suffering from colorblindness than females. Explain.

(2 marks)