Practice question

For a locus with two alternative alleles A and a, frequencies conventionally designated p for A and q for a. Since each gene copy must be either A or a, total proportion sums to 100% of alleles. Mathematically p + q = 1 by definition of allele frequency partition. Genotype frequencies under Hardy-Weinberg become p², 2pq, q² also summing to 1. Relationship ensures if one allele frequency known other automatically determined, essential for estimating carrier frequencies for recessive diseases from disease prevalence using square root approximation.