An inversion refers to a type of mutation where chromosomal rearrangement takes place in a single chromosome. It can be of two types: Paracentric Inversion and Pericentric Inversion.
Pericentric inversion occurs in the chromosomes that leads to abnormal gametes where some genes are missing.
Abnormal gametes associated with a heterozygous pericentric inversion result from crossing over which is characterized by two-break events within the chromosome (short arm and the long arm).