A mutation that introduces a stop codon into a gene is classified as which type of mutation?

A mutation that introduces a stop codon into a gene is classified as a nonsense mutation. This type of mutation occurs when a single nucleotide change results in a premature stop codon, which can drastically alter the final protein product. The introduction of this stop codon leads to early termination of protein synthesis, resulting in a truncated protein that is often nonfunctional.

In contrast, a missense mutation involves a change in a single nucleotide that results in the substitution of one amino acid for another in the protein sequence, while a frameshift mutation results from insertions or deletions of nucleotides that alter the reading frame of the gene. A silent mutation changes a nucleotide but does not affect the amino acid sequence of the protein due to the redundancy in the genetic code. Hence, the classification of the mutation as a nonsense mutation is accurate because it specifically describes the introduction of a stop codon leading to early termination of translation.