Question

Which describes pleiotropy?

Answer 1

Pleiotropy occurs when one gene will code and control the phenotype or expression of several different and unrelated traits. Pleiotropy is most often a bad thing, as many diseases are due to a gene controlling so many traits at once. For example, phenylketonuria is a disease caused by pleiotropy.

Answer 2

Pleiotropy occurs when one gene influences two or more seemingly unrelated phenotypic traits.