2. Traits controlled by multiple alleles produce more than three

Phenotypes

Explanation:

If a trait is simply controlled by 2 alleles, there is a maximum of three phenotypes that can be produced from the alleles. Either the individual is homozygous dominant (AA), homozygous recessive (aa), or heterozygous (Aa). This would give a maximum of 3 different phenotypes, potentially only 2 phenotypes if the trait is completely dominant

In contrast, if a trait is controlled by lots of alleles (either at the same gene or different genes) there are many more possibilities for the final phenotype, as each allele might contribute something slightly different.