Several types of mutation are identified and described in the chapter. These include (1) promoter mutation, (2) splice site mutation, (3) missense mutation, (4) frameshift mutation, and 5) nonsense mutation. Match the following mutation descriptions with the type(s) of mutations listed above. More than one mutation type might match a description.

A mutation that produces a protein that is shorter than the wild-type protein but does not have any amino acid changes in the portion produced.

Key Concepts

Nonsense Mutation

A nonsense mutation is a type of point mutation where a single nucleotide change results in a premature stop codon in the protein sequence. This leads to the production of a truncated protein that is shorter than the wild-type protein. Nonsense mutations can significantly impact protein function, often resulting in loss of activity or stability.

Frameshift Mutation

Frameshift mutations occur when nucleotides are inserted or deleted from the DNA sequence, causing a shift in the reading frame of the codons. This alteration can lead to a completely different translation from the original, often resulting in a nonfunctional protein. While frameshift mutations typically produce longer or shorter proteins, they can also lead to premature stop codons.

Missense Mutation

A missense mutation is a type of mutation where a single nucleotide change results in the substitution of one amino acid for another in the protein sequence. This can affect the protein's function, depending on the role of the altered amino acid. However, in the context of the question, a missense mutation would not produce a shorter protein without any amino acid changes in the remaining sequence.