A mutation that introduces a change that alters gene function is known as a missense mutation or a nonsense mutation. Missense mutations result in a single nucleotide change that leads to a different amino acid being incorporated into a protein, potentially altering its function. In contrast, nonsense mutations create a premature stop codon, leading to truncated proteins that lack functional activity. Such mutations are significant in evolution and can lead to various genetic disorders or contribute to the development of cancer by affecting how cells grow and reproduce.