Explanations:
The Punnett square is a square diagram that is used to predict the genotype of a particular cross or breeding experiment. It is named after Reginald C. Punnett, who devised the approach. The diagram is used by biologists to determine the probability of an offspring having a particular genotype. By the Punnett square with the cross AaBb × Aabb, there are 4 AaBb genotypes.