What type of mutation occurs when the order of genes in a chromosome is reversed?

The correct choice is the one that identifies the specific mutation type where the sequence of genes within a chromosome is reversed, which is known as inversion. An inversion mutation occurs when a segment of a chromosome breaks off, flips around, and reattaches to the same chromosome, but in the reverse orientation. This can affect gene expression and can have significant biological consequences, as the altered order of the gene sequence may disrupt the normal regulatory mechanisms that control how these genes are expressed.

In contrast, other types of mutations involve different changes to the genetic material. Deletion involves the loss of a segment of the chromosome, and insertion refers to the addition of extra nucleotides into a DNA sequence. Translocation involves a segment of DNA breaking off from one chromosome and attaching to a different chromosome. Understanding the specifics of these mutations helps in studying genetic diseases and variations.