A single,simple,recessively inherited mutation inactivates the enzyme that converts phenylalanine to tyrosine.Homozygous recessive individuals possess an excessive amount of phenylalanine and a deficiency of tyrosine.Additionally,these individuals may be mentally deficient,have abnormally light hair and abnormally light skin color.This disorder is an example of
A)incomplete penetrance.
B)incomplete dominance.
C)polygenic inheritance.
D)pleiotropy.

Question

Quizplus · Accepted Answer

Pleiotropy occurs when one gene influences multiple phenotypic traits. In this case, the single mutation affects multiple characteristics such as mental ability, hair color, and skin color.

A Single,simple,recessively Inherited Mutation Inactivates the Enzyme That Converts Phenylalanine