Punnett squares Sperm Sperm Genotype combination A-allele a-allele of alleles at a specific locus ggs AA aA A-allele Eggs aa a-allele Sperm Sperm A-allele a-allele Eggs AA aA unaffected A= normal(major) allele A-allele a= mutated(minor)allele ggs aa affected a-alleleSperm A-allele Sperm a-allele Eggs A-allele AA aA Eggs a-allele Aa aa “Punnett squares” Sperm A-allele Sperm a-allele Eggs A-allele AA aA Eggs a-allele Aa aa A = normal (major) allele a = mutated (minor) allele affected A a Genotype = combination of alleles at a specific locus unaffected