Under Hardy-Weinberg **equilibrium**,
**allele** and **genotype** frequencies remain constant over generations.

- The
**allele frequencies**are described by*p*+*q*= 1,*p*is the**dominant**allele frequency and*q*is the**recessive**allele frequency. - The
**genotype frequencies**are described by*p*+ 2^{2}*pq*+*q*= 1,^{2}*p*and^{2}*q*are frequencies of the^{2}**homozygous**genotype and 2*pq*is the frequency of the**heterozygous**genotype.