Question: how many possible genotype combinations would there be?
Answer: Genotype is also used to refer to the pair of alleles present at a single locus. With alleles 'A' and 'a' there are three possible genotypes AA, Aa and aa. With three alleles 1, 2, 3 there are six possible genotypes: 11, 12, 13, 22, 23, 33. First we must appreciate that genes do not act in isolation.