Practice question

Hardy-Weinberg partitions allele frequencies p and q into genotype classes after random gamete union. Homozygous dominant AA requires receipt of A allele from both sperm and egg, probability p multiplied by p equals p squared. Similarly recessive homozygote aa is q squared and heterozygote is two pq, summing to one for total population. Symbol p alone denotes allele frequency, not genotype frequency, while two pq denotes heterozygotes. Therefore representation of dominant homozygote relies on squaring allele frequency, cornerstone for predicting dominant trait prevalence and for inferring allele frequencies from dominant phenotypes.