Some phenotypes are either or- (either have the traits or don"t have) Some are gradations - (2 or more genes) Fixed alleles = all individuals either ww or ww - no variation. If fixed alleles is dominant, there may not be a homozygous recessive) Example: webbed feet (ww) & no webbed feet (ww/ww) Gene pool = all alleles of all genes in a population. Allele frequency = proportion of a specific allele (w/w) in a population. Example: 1/2 population of alleles are w and 1/2 population are w. This can mean that 1/2 population are ww or 1/2 ww or 100% heterozygous ww. Frequency of organisms in population p^2 + 2pq + q^2 = 1 or 100% Frequency of alleles p + q = 1. You can calculate the gene frequencies if you know the phenotypes. Example: the frequency of w is . 7 or 70% and w is . 3 or 30% p = 0. 7 and q = 0. 3.