Chromosomal Crossover

Non-sister Chromatids

These are chromatids of homologous chromosomes. While sister chromatids are exact copies of each other, non-sister chromatids code for the same genes but are not genetically identical.


Chiasma is the point of contact between two non-sister chromatids to exchange DNA, also called crossing over. It occurs during meiosis and produces a new combination of genes.