Assume that a population is in hardy-weinberg equilibrium for a particular gene with two alleles, a and a. the frequency of a is p, and the frequency of a is q. because these are the only two alleles for this gene, p + q = 1.0. if the frequency of homozygous recessive individuals (aa) is 0.04, what is the value of q? based on the value of q, find p. then use the values of p and q to calculate the frequency of the heterozygote genotype (aa).