Number of gametes produced by a homozygous and a heterozygous individuals of genotype AA and Aa, respectively are

The formula to calculate the number of gametes from a given genotype is 2n.where, n = number of heterozygosity in the given genotype. Thus , number/types of gametes produced by a homozygous individual of genotype AA is 2(0) = 1 and by heterozygous individual of genotype Aa is 2(1) = 2.