What is the difference between polygenic and pleiotrophy?

Question

?

Answer 1

Polygenic - pertaining to two or more genes, an example is eye color - it takes many genes to come up with your eye color

Pleiotropy - when one gene affects many phenotypic traits. A classic example of pleiotropy is the human disease PKU (phenylketonuria). This disease can cause mental retardation and reduced hair and skin pigmentation, and can be caused by any of a large number of mutations in a single gene that codes for an enzyme (phenylalanine hydroxylase) that converts the amino acid phenylalanine to tyrosine, another amino acid.