Question 2

How many phenotypes would be present in the F2 for protein percent assuming that environment does not influence the trait? 

To answer this question we need to understand how additive gene action will influence protein. As we said earlier, the highest possible protein would be from a plant that has the maximum number of additive or plus alleles. In this cross it would be AABBDDEEFFGGHH which has 14 additive alleles. The progeny with the lowest possible number of additive alleles would be aabbddeeffGGhh which has two additive alleles. Therefore a progeny can have from 14 to 2 additive alleles or 13 categories of additive alleles. Thus we should see 13 protein phenotypes if environment does not impact variation in this trait. If environment does shift protein up or down slightly from seed to seed, then many additional protein levels will be observed because genotype plus environment will control this trait.