Practice question

Under Hardy-Weinberg equilibrium, heterozygotes arise via two complementary gamete combinations: A-bearing sperm with a-bearing egg and vice versa. Probability of first combination is p multiplied by q, reciprocal is q multiplied by p, summing to two pq. This term quantifies heterozygosity in randomly mating population and represents individuals carrying two different alleles. While p squared and q squared denote both homozygote classes, two pq captures outbred genotype frequency. Deviation from two pq suggests inbreeding, population substructure, or selection, making it central for estimating carrier frequencies.