Suppose a population of flour beetles has 1,000 individuals.Normally the beetles are red; however, this population is polymorphic for a mutant autosomal body color, black, designated by bb.Red is dominant to black, so BB and Bb genotypes are red.Assume the population is at Hardy-Weinberg equilibrium, with equal frequencies of the two alleles.What would be the expected frequencies of the homozygous dominant, heterozygous, and homozygous recessive genotypes (in that order) after 100 generations, assuming that no selection or other evolutionary processes were operating?
A) 0.25, 0.5, 0.25
B) 0.75, 0.20, 0.05
C) 0, 0.5, 0.5
D) 0, 0, 1
E) 1, 0, 0

Question

Quizplus · Accepted Answer

At Hardy-Weinberg equilibrium with equal allele frequencies, the genotype frequencies are given by p^2, 2pq, and q^2, where p and q are the allele frequencies for the dominant and recessive alleles, respectively. With equal frequencies (p = q = 0.5), the expected genotype frequencies are (0.5)^2 = 0.25 for homozygous dominant (BB), 2(0.5)(0.5) = 0.5 for heterozygous (Bb), and (0.5)^2 = 0.25 for homozygous recessive (bb).

Suppose a Population of Flour Beetles Has 1,000 Individuals