What is the Hardy-Weinberg equation for genotype frequency?

The Hardy-Weinberg equation for genotype frequency is a fundamental principle in population genetics that describes how allele frequencies in a population relate to genotype frequencies when the population is in equilibrium. This equation states that the sum of the frequencies of the homozygous dominant genotype (p²), the heterozygous genotype (2pq), and the homozygous recessive genotype (q²) is equal to one.

In this context, p represents the frequency of the dominant allele, while q represents the frequency of the recessive allele. The term p² accounts for individuals that are homozygous dominant, 2pq accounts for heterozygous individuals, and q² accounts for individuals that are homozygous recessive. This equation enables researchers to predict the expected genotype frequencies in a population, assuming no evolution is occurring, meaning that conditions such as mutation, selection, migration, and genetic drift are absent.

The other options do not accurately represent the Hardy-Weinberg principle. For instance, the first option (p + q = 1) is related to allele frequencies rather than genotype frequencies. Option three (p³ + q³ = 1) does not relate to the Hardy-Weinberg principle at all, and the fourth option