How do you read a Punnet Square?

Answer 1

Reading a punnet square is much like reading a grid map. Start with one finger on the father allele and one on the mother allele and find where they meet in the middle, the combination of both the father allele and the mother allele will give you the genotype. Repeat for all four middle squares. In all punnet squares, the dominate gene is the capital letter (e.g R) and the recessive gene is the normal letter (e.g r). When two dominate alleles show (RR) the phenotype will show the dominate gene. When one dominate and one recessive allele show the dominate gene will still show (Rr), in females they call it them a carrier female because they carry the recessive allele as well. When two recessive alleles show (rr) the recessive feature will show in the phenotype.