Final answer:
A chromosome inversion is a 180-degree rotation of a DNA segment on a chromosome, reattached at its original location, which can cause functional genetic changes.
Step-by-step explanation:
A chromosome inversion refers to a chromosomal structural change where a segment of DNA is detached, turns 180 degrees, and is then reinserted back into its original location in the chromosome. This genetic alteration involves a physical reversal of the DNA sequence and can occur as a result of mechanical shear or the activity of transposable elements, which are special DNA fragments that can facilitate the rearrangement of chromosome segments.
Although inversions typically do not lead to significant genetic disorders unless they disrupt a specific gene sequence, they can cause functional changes if they affect the positioning of gene regulatory elements. This can lead to abnormalities in gene expression. A pericentric inversion includes the chromosome's centromere, whereas a paracentric inversion occurs outside the centromere.