There are three types of point mutations in DNA. There are (1) silent mutations, (2) missense mutations, and (3) nonsense mutations. In silent mutations, a base is replaced by another but the amino acid encoded by the codon remains the same (due to many codons code for the same amino acid). In missense mutations, a base pair is replaced by another, now the amino acid encoded by the codon is now different. This will render the final protein product dysfunctional. Lastly, in nonsense mutations, a base pair is replaced by another and the resulting codon will be a stop codon (UAG, UAA, UGA). This results to a premature termination of protein elongation leading to fragmented nonfunctional protein.
