This activity is to be used when introducing students to basic genetic pedigrees. Students should have some background on how a pedigree is set-up and how to read one. Students will work in groups and use pom poms, representing genes, to see how variations are passed on from grandparents, to parents, to children. This allows students to see how grandchildren not only inherit variations from their parents, but also from grandparents. It also helps students see how half their genes come from one parent, and half come from the other.