Non-sister Chromatids

The crossover between non-sister chromatids on homologous chromosomes at meiotic prophase I produces a dicentric chromatid at Anaphase I. A bridge configuration results at Anaphase I.

During meiosis I a crossover between homologous chromosomes occurs. One homologe is normal and has a terminal knob. The other homologe does not have a terminal knob, but has a duplication on one arm. The dicentric chromatid forms a bridge at Anaphase I. The acentric chromosome is missing a centromere and is no longer able to participate in meiosis or mitosis. The dicentric chromosome will break and the break will usually result in a deficiency in one segment with a small duplication in the complimentary segment.