Question

. In the fruit fly, Drosophila melanogaster, the normal wild type has long wings and red eyes (both are dominant traits). Recessive forms of these genes result in vestigial wings and brown eyes. A red-eyed, vestigial winged male is crossed with a brown-eyed, long-winged female. (2 pts) a) Assuming each parent is homozygous for the dominant alleles, write out the cross and give the genotype and phenotype of the offspring. b) If each parent is a heterozygote for the dominant alleles, what are the genotypes, phenotypes and ratios of the potential offspring?

Answer 1

No body?!

Answer 2

Eye: red is dominant so let us write as 'E', and brown is recessive so let us write as 'e'
Wings: long is dominant so let us write as 'W', vestigial is recessive so let us write as 'w'

In the question, the male is red eyed and vestigial wing. The eye can be homozygous dominant (EE) or heterozygous dominant (Ee). The vestigial wing is recessive (ww). The genotype of the male can be EEww or Eeww.

The female is brown eyed and long wing. The brown eye is recessive (ee). The long wing can be homozygous dominant (WW) or heterozygous dominant (Ww). . The genotype of the female can be eeWW or eeWw.

Answer 3

Question a: the parents are homozygous for the dominant alleles, so the male is EEww and female is eeWW.