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. Silent mutations
• B. Missense mutations
• C. Nonsense mutations
• D. Point mutations

Answer: (B)

A missense mutation changes the nucleotide in a codon so that it encodes a different amino acid. Because the genetic code maps each codon to a specific amino acid, even a single base change can swap one amino acid for another in the growing protein, altering its properties and possibly its function. Silent mutations don’t change the amino acid because the codon redundancy means different codons can specify the same amino acid, so the protein stays the same. Nonsense mutations turn a codon into a stop signal, truncating the protein rather than altering an amino acid. Point mutations describe a single-nucleotide change in a codon but do not specify the outcome; they include missense, nonsense, and silent changes. So the mutation that results in a different amino acid being incorporated is the missense mutation.

A missense mutation changes the nucleotide in a codon so that it encodes a different amino acid. Because the genetic code maps each codon to a specific amino acid, even a single base change can swap one amino acid for another in the growing protein, altering its properties and possibly its function.

Silent mutations don’t change the amino acid because the codon redundancy means different codons can specify the same amino acid, so the protein stays the same. Nonsense mutations turn a codon into a stop signal, truncating the protein rather than altering an amino acid. Point mutations describe a single-nucleotide change in a codon but do not specify the outcome; they include missense, nonsense, and silent changes. So the mutation that results in a different amino acid being incorporated is the missense mutation.