A dominant allele H reduces the number of bristles that Drosophila flies have, giving rise to a "hairless" phenotype. In the homozygous condition, H is lethal. An independently assorting dominant allele S has no effect on bristle number except in thje presence of H in which case a single dose of S supressess the hairless phenotype, thus restoring the hairy phenotype. However, S also is lethal in the homozygous (S/S) condition

a. What ratio of hairy to harless flies would you find in the live progeny of a cross between two hairy flies both carrying H in the supressed condition?

b. When the hairless progeny are backcrossed with a parental hairy fly, what phenotypic ratio would you expect to find among their live progeny?