What type of mutation involves the addition of one or more nucleotides into a segment of DNA?

The addition of one or more nucleotides into a segment of DNA is known as an insertion mutation. This type of mutation can alter the reading frame of the genetic code, potentially leading to significant changes in the resulting protein. Insertion mutations can occur due to various mechanisms, such as errors during DNA replication or as a result of the activity of transposable elements, also known as "jumping genes."

Such mutations can have varying effects on an organism, including benign variations or serious genetic disorders, depending on where in the genome the insertion occurs and how it affects gene function. The significance of insertion mutations lies in their ability to introduce new genetic material and thus change the protein encoding, which can have profound biological implications.