What explains why human eyes come in a variety of colors?
A. Multiple genes each have only one allele.
B. Multiple alleles result in many phenotypes.
C. Different phenotypes result in different genes.
D. Many phenotypes have pairs of alleles.
B. Multiple alleles result in many phenotypes.
The color of human eyes is determined by the amount and type of pigments in the iris. The pigments depend on the genes that a person has inherited from their parents. There are several genes involved in eye color, and each gene has different variations called alleles. The combination of alleles a person inherits from their parents determines the color of their eyes. Because there are many different possible combinations of alleles, there is a wide variety of eye colors in humans. Therefore, the presence of multiple alleles results in a range of phenotypes (eye colors) in humans.