Punnett Squares

5. Using a Punnett Square

Using a Punnett Square

A Punnett square is a chart that allows you to easily determine the expected percents of different genotypes in the offspring of two parents. An example of a Punnett square for pea plants is shown in Figure below. In this example, both parents are heterozygous for flower color (Bb). The gametes produced by the male parent are at the top of the chart, and the gametes produced by the female parent are along the side. The different possible combinations of alleles in their offspring are determined by filling in the cells of the Punnett square with the correct letters (alleles).


At the link below, you can watch an animation in which Reginald Punnett, inventor of the Punnett square, explains the purpose of his invention and how to use it.

http://www.dnalc.org/view/16192-Animation-5-Genetic-inheritance-follows-rules-.html


Watch the following explanation of Punnett squares:


Wathc the following example of the use of a Punnett square.



Punnett Square.

This Punnett square shows a cross between two heterozygotes. Do you know where each letter (allele) in all four cells comes from?



CK-12 Foundation, Biology. http://creativecommons.org/licenses/by-nc-sa/3.0/