Which type of mutation does not alter the amino acid sequence?

A silent mutation is a specific type of mutation that does not change the amino acid sequence of a protein. This occurs because of the redundancy in the genetic code; multiple codons can encode for the same amino acid. For example, a mutation in the DNA sequence that changes one codon to another codon that still codes for the same amino acid would be considered a silent mutation.

In contrast, missense mutations result in a different amino acid being incorporated into the protein, potentially altering its function. Nonsense mutations introduce a premature stop codon, leading to a truncated protein. Frameshift mutations, caused by the insertion or deletion of nucleotides, shift the reading frame and change the entire sequence of amino acids downstream from the mutation. Thus, silent mutations maintain the integrity of the protein's amino acid sequence, while the other types of mutations alter it in some way.