This activity is suitable for AP Biology or other advanced Biology students and classes. Students will need an ear or packet of genetic corn representing the results of a dihybrid cross such as heterozygous smooth, heterozygous purple (SsPp X SsPp), as well as access to a calculator. The activity involves data collection and assessment of the results of the cross to analyze the "goodness of fit" using the chi square calculation. Four additional practice problems with genetic crosses, hypothetical results and requirements for "goodness of fit" assessment are included in the activity. Teaching the class how to do dihybrid crosses, incomplete dominance crosses and chi square computations and assessment is recommended before beginning this activity. An answer key for the additional problems is included. The zip file contains the four page lab as well as the answer key in both word and pdf format.