Answer
Mutations in a single gene can lead to a defect in only one enzyme in the metabolic pathway. Mnemonic: One gene, one enzyme
Each polypeptide is coded by a different gene and a protein consists of multiple polypeptides. Mnemonic: one gene, one polypeptide
Work Step by Step
Mutations in a single gene can cause a defect in only one enzyme in a metabolic pathway. (One-gene, one-enzyme)
Each polypeptide is coded by a separate gene; multiple polypeptides compose a protein. (One-gene, one-polypeptide) *a protein is not coded by one gene!