Your father is heterozygous for the recessive disorder phenylketonuria (PKU). You know your mother has two "good" alleles. You have a ____chance of having the disorder.
A) 0%
B) 100%
C) 25%
D) 50%
E) 75%

Question

Quizplus · Accepted Answer

Since your father is heterozygous, he has one recessive allele for PKU and one normal allele. Your mother has two normal alleles. Therefore, you can only inherit a normal allele from your mother and either a normal or a recessive allele from your father, making it impossible for you to have two recessive alleles and thus the disorder.

Your Father Is Heterozygous for the Recessive Disorder Phenylketonuria (PKU)