The recessive allele s causes Drosophila to have small wings and the s + allele causes normal wings. This gene is known to be X-linked.

a. If a small-winged male is crossed with a homozygous wild-type female, what phenotypic ratio of normal to small-winged flies can be expected overall and by each sex in the F1? Show the Punnet square.

b. If F1 flies are intercrossed, what F2 progeny phenotypic ratios are expected overall and by sex Show the Punnett square.

c. What progeny phenotypic ratios overall and by sex are predicted if F1 females are backcrossed to their father? Show the Punnett square.