Punnett Squares

Punnett Squares are a convenient way to predict and explain inheritance. They only work if there are only two options for a gene (two possible alleles), and if the characteristic is controlled by only one gene (set of alleles).

By completing a Punnett Square, we can predict the probability of an offspring (child) having a certain characteristic (phenotype) and having a certain genotype (homozygous dominant, heterozygous, or homozygous recessive).

If you would prefer my explanation, here it is (although I think the Amoeba Sisters do a much better job of it!!)