1. [12 marks] A single gene controls two human physical characteristics: the ability to roll one's tongue (or not) and whether one's ear lobes are free of (or attached to) the neck. Genetic theory says that people will have neither, one, or both of these traits in the ratios 9:3:3:1. A class of Biology students collected data on themselves and reported the following frequencies:

Tongue, Non-curling, Curling, Non-curling, Curling, Earlobe Attached Attached Free Free Count 64 34 25 6