Final answer:
Chromosome inversion refers to the reversal of a chromosome segment's order after it detaches, rotates 180 degrees, and attaches itself to the chromosome. It could alter gene orientation but often has mild effects if it does not disrupt any genes.
Step-by-step explanation:
When the order of a segment of a chromosome is reversed, this is referred to as a chromosome inversion. A chromosome inversion involves the detachment, 180° rotation, and subsequently the reinsertion of that segment into the same chromosome. This kind of structural rearrangement in the chromosome may occur naturally due to mechanical shear or by the actions of transposable elements.
Inversions may result in altered gene orientation which potentially leads to changes in gene expression when regulatory elements get misaligned with their target genes. Nonetheless, if none of the involved gene sequences are disrupted, the effect of inversions on the organism's phenotype can be relatively mild compared to aneuploid errors.