In fruit flies the brown gene which controls eye color is lo

In fruit flies, the brown gene, which controls eye color, is located on an autosome. Brown mutants (bw) have brown eyes, while wild-type flies (bw^+) have red eyes. A gene on the X chromosome, miniature, controls wing size. Miniature wings are caused by the m allele, which is recessive to the allele for normal wings (m^+). True-breeding miniature-winged, red-eyed females are crossed to true-breeding normal-winged, brown-eyed males. Predict the phenotypes (including their ratios of the F1 flies. If the F1 flies are intercrossed with each other, what phenotypes will appear in the F2 and in what proportions?

Solution

1.

Phenotype

Normal wings        Red Eyes             4418

Miniature wings    Brown eyes          4330

Normal wings        Brown eyes         610

Miniature wings    Red eyes              590

2. The F1 was self-crossed to give rise to the F2 generation. Of these offspring, 3/4 had brown eyes while 1/4 had Red eyes. Phenotypic ratio is 3:1