This video clip from the BBC (from the TV series Botany: A Blooming History) looks at how geneticists in the early 20th century investigated the puzzle of the inheritance of characteristics.
In 1903, Bateson found that snapdragon flower colour did not follow the pattern of inheritance seen in other species he had looked at. His student and collaborator Muriel Wheldale worked on the puzzle for 4 years, cross-pollinating selected flowers by hand, then sowing the seed and observing the flowers of the resulting plants. She established that there are several genes which influence flower colour. Hence the inheritance of characteristics is due to the interactions of many genes with different forms. An understanding of these interactions enables us to predict the phenotype of offspring from particular individuals.
Use to introduce more complex patterns of inheritance to more confident students. These can include ideas of co-dominance, epistasis etc. Students can then be encouraged to develop skills in complex problem solving.
See this on the BBC Class Clips site