Question

pku homozygotes lack an enzyme required for the conversion of the amino acid phenylalanine to _______. adenine cytosine tyrosin guanine

Explanation:

Phenylketonuria (PKU) is a genetic disorder where homozygotes lack the enzyme phenylalanine - hydroxylase which is needed to convert phenylalanine to tyrosine. Adenine, cytosine, and guanine are nucleic - acid related and not the product of phenylalanine conversion.

Answer:

C. Tyrosine