Ace the AP Biology Challenge 2026 – Unleash Your Inner Scientist and Conquer the Course!

The term "inversion" in genetics refers to the rearrangement of a segment of DNA within a chromosome in such a way that the sequence of genes is reversed. This occurs when a segment of a chromosome breaks off, flips around, and reattaches in the opposite orientation. Inversions can impact gene expression and lead to significant effects on an organism's phenotype, especially if they disrupt important genes or regulatory elements. This genetic alteration can also play a role in evolution and speciation, as it may result in new combinations of traits that are subject to natural selection.

The other options describe different genetic phenomena: removing a segment from a chromosome is known as a deletion, duplicating a DNA segment is referred to as duplication, and nondisjunction involves the failure of homologous chromosomes or sister chromatids to separate properly during cell division, leading to an abnormal number of chromosomes.