Many traits (phenotypes), like eye color, are controlled by multiple genes. If eye color were controlled by the number of genes indicated below, how many possible genotype combinations would there be in the following scenarios?

a. 5 Genes:

b. 10 Genes:

c. 20 Genes:

If there are 5 genes, let us assume that they are in the alternative forms with 2 possible gets for each five ... So we have

2 possible gametes for each five = 2 to the power of 5 = 32 gametes

Then genotypes = 3 to the power of 5 = 243

The same also for 10 genes

2 possible gametes for each 10 = 2 to the power of 10 = 1024 gametes

Then genotypes = 3 to the power of 10 = 59,049

The same also for 20 genes

2 possible gametes for each 20 = 2 to the power of 20 = 1,048,576

Them genotypes = 3 to the power of 20 = 3,486,784,401