Advanced Placement (AP) Biology 2025 – 400 Free Practice Questions to Pass the Exam

The term "deletion" specifically refers to the process in genetics where a segment of DNA is removed from the chromosome. This can occur in various ways, such as through errors during DNA replication or as a result of environmental factors. When a deletion happens, the genetic information contained in that segment is lost, which can have significant impacts on gene expression and organism phenotype. This loss of genetic material can lead to various genetic disorders or diseases, depending on the genes and regulatory elements that were deleted.

This definition distinguishes it clearly from other genetic changes. For instance, repeating a segment of DNA pertains to duplications, reversing a segment involves inversions, and moving a segment to another chromosome is referred to as translocation. Each of these processes alters the genetic material in different ways, but only deletion directly refers to the removal of a segment.