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
• B. Missense
• C. Insertion
• D. Deletion

Answer: (B)

A change that alters a codon so it specifies a different amino acid is a missense mutation. This type of mutation keeps the reading frame intact and changes only one amino acid in the protein, which can affect structure or function depending on how different the new amino acid is from the original. This differs from a nonsense mutation, which changes a codon into a stop signal and truncates the protein, and from insertion or deletion mutations, which add or remove nucleotides and often shift the reading frame (frameshift), altering many downstream amino acids. Missense mutations specifically alter the identity of the amino acid at a given position without altering the rest of the reading frame.

A change that alters a codon so it specifies a different amino acid is a missense mutation. This type of mutation keeps the reading frame intact and changes only one amino acid in the protein, which can affect structure or function depending on how different the new amino acid is from the original.

This differs from a nonsense mutation, which changes a codon into a stop signal and truncates the protein, and from insertion or deletion mutations, which add or remove nucleotides and often shift the reading frame (frameshift), altering many downstream amino acids. Missense mutations specifically alter the identity of the amino acid at a given position without altering the rest of the reading frame.