Paracentric inversions in meiosis: In an individual heterozygous for paracentric inversion (does not include centromere): ~ an inversion loop forms ~if crossing over occurs within the loop: 2 chromatids are not involved in crossover, one dicentric chromatid (2 centromeres) and one acentric fragment ( no centromere) form. The Dicentric bridge breaks during anaphase 1, the acentric fragment is lost. ~ of the 4 gametes, 2 containing non recomb chromos ( 1 normal, 1 with inversion) , the other 2 contain recomb chromos missing some genes, these are not viable.