Q. Two different strains of fies are each homozygous for different recessive mutant alleles of the short wing gene (sw^1 ans sw^2). Strain 1 is also heterozygous for dominant green-eye mutant allele (G); Strain 2 is also heterozygous for a dominant hairy leg mutant allele (H). All three genes (G, sw, H) are related and in order [G,sw,H] on chromosome.

Strain 1 males are crossed to Strain 2 females, and the F1 are crossed to sw^1 homozygote. One hundred thousand F2 progeny are observed; all of F2 have short wings except for 10 of them that have normal wings. The 10 with normal wings also have mutant green eyes and mutant hairy legs.

a. The 10 F2 with normal wings are not revertants. Elucidate where they came from with an easy diagram.

b. sketch a map showing the positions of G, sw^1, sw^2, and H on teh chromosome.