Final answer:
A chromosomal inversion refers to the detachment, 180° rotation, and reinsertion of a chromosome segment, changing the gene orientation. It can have various effects on gene functionality, especially if it disrupts gene sequences or affects gene regulators.
Step-by-step explanation:
A chromosomal change in structure in which a segment of DNA is rotated 180 degrees is referred to as a(n) inversion. This chromosomal mutation involves the detachment of a chromosome segment, its rotation, and reinsertion back into the chromosome. Chromosome inversions can be either pericentric, including the centromere, or paracentric, occurring outside of the centromere. While they typically result in gene orientation change without losing genetic material, inversions can have significant effects if they disrupt gene sequences or alter the positions of gene regulators, leading to abnormal levels of gene products. In comparison, other types of mutations like deletion, duplication, and translocation involve loss or gain of genetic material, or the exchange of segments between non-homologous chromosomes.