In the peppered moth (Biston betularia), black individuals may be either homozygous (A1A1) or heterozygous (A1A2), whereas pale gray moths are only homozygous (A2A2). Suppose that in a sample of 250 moths from one locality, 108 are black and 142 are gray. (a) Which allele is dominant? (b) Assuming that the locus is in Hardy-Weinberg equilibrium, what are the allele frequencies? (c) Under this assumption, what proportion of the sample is heterozygous? What is the number of heterozygotes?