Which mutation changes a codon to code for a different amino acid?

Which mutation changes a codon to code for a different amino acid?

• A. Nonsense mutation
• B. Silent mutation
• C. Missense mutation
• D. Frameshift mutation

Answer: (C)

When a single nucleotide change causes a codon to specify a different amino acid, the protein’s sequence at that position is altered. This is a missense mutation. It directly changes which amino acid is added during translation, which can affect protein structure and function depending on the properties of the new amino acid and its position. In contrast, a nonsense mutation creates a stop codon and truncates the protein; a silent mutation changes the codon to a synonymous one that still codes for the same amino acid; and a frameshift mutation shifts the entire reading frame due to an insertion or deletion, altering many downstream codons. The described scenario matches a missense mutation because only the encoded amino acid changes.

When a single nucleotide change causes a codon to specify a different amino acid, the protein’s sequence at that position is altered. This is a missense mutation. It directly changes which amino acid is added during translation, which can affect protein structure and function depending on the properties of the new amino acid and its position.

In contrast, a nonsense mutation creates a stop codon and truncates the protein; a silent mutation changes the codon to a synonymous one that still codes for the same amino acid; and a frameshift mutation shifts the entire reading frame due to an insertion or deletion, altering many downstream codons. The described scenario matches a missense mutation because only the encoded amino acid changes.