What characterizes a paracentric inversion?

A paracentric inversion is characterized by the exclusion of the centromere from the inverted segment of the chromosome. In a paracentric inversion, the segment that undergoes the inversion occurs entirely on one arm of the chromosome, meaning the centromere is not included within this rearrangement.

This structural change in the chromosome can affect gene expression and can lead to difficulties during meiosis, particularly because the recombination events can result in the formation of non-viable gametes. While paracentric inversions can lead to structural abnormalities in the resulting gametes, the defining feature lies in the specific location of the inversion relative to the centromere, which is that it does not involve the centromere itself.