Final answer:
In genetics, the selection coefficient measures the relative fitness of a genotype, and the heterozygote effect describes differing fitness levels among genotypes. Hardy-Weinberg equations are used to predict genetic structure and estimate genotype frequencies in a population.
Step-by-step explanation:
When studying genetics, specifically population genetics, the selection coefficient (s) is a measure of the relative fitness of a particular genotype compared to the other genotypes in the population. It can be used to predict the changes in allele frequency over time. The selection coefficient (s) can be calculated using the fitness values of genotypes. For a heterozygote genotype (Aa), if the fitness of the homozygous dominant (AA) is 1, and the fitness of Aa is 1-s, with s being the selection against the heterozygote. The heterozygote effect refers to the phenomenon where the heterozygote genotype has a different fitness level compared to both the homozygous dominant and recessive genotypes.
The Hardy-Weinberg equation is instrumental in understanding genetic structure: p² + 2pq + q² = 1, where p is the frequency of the dominant allele A, and q is the frequency of the recessive allele a. To estimate the genotype frequencies, you multiply the allele frequencies accordingly. For example, the frequency of the AA genotype is calculated as p². If p is 0.7 and q is 0.3, then AA frequency would be 0.7² = 0.49. As all genotype frequencies must add up to 1, the frequency of heterozygotes (Aa) can be calculated as 2pq, which in this example would be 2(0.7)(0.3) = 0.42.