Which of the following describes a frameshift mutation?

A frameshift mutation specifically refers to a type of genetic mutation that occurs when there is either a deletion or an insertion of nucleotides in a DNA sequence that is not a multiple of three. This alteration shifts the reading frame of the genetic code, which means that every subsequent codon (the three-nucleotide sequence that codes for an amino acid) is read incorrectly.

Because proteins are synthesized based on the sequence of codons, a frameshift mutation can lead to the production of completely different and often nonfunctional proteins, potentially leading to significant changes in the organism. This is distinct from a change in a single base pair, which may or may not have critical effects on protein synthesis, as well as other types of mutations that involve errors in transcription or mutations that do not impact protein production at all.

Understanding frameshift mutations is crucial in genetics and molecular biology, as they can lead to serious consequences, such as genetic disorders or diseases, by disrupting the normal functioning of genes.