Which mutation results in part of a DNA sequence being missing?

A deletion mutation involves the removal of one or more nucleotides from a DNA sequence. This type of mutation directly results in a segment of the genetic code being absent, which can lead to significant changes in the resulting protein if the deletion occurs within a coding region. The missing DNA can disrupt the reading frame during translation, potentially leading to the production of a nonfunctional protein.

On the molecular level, a deletion alters the structure of the DNA strand, causing a shift in how the genetic information is processed by the cellular machinery. If the deletion affects critical regions of the gene, it may have severe implications for the organism's phenotype, such as genetic diseases or dysfunctions. Understanding deletion mutations is crucial in genetics and can be foundational in fields like biotechnology and medicine, where genetic manipulations are common.