Now, when crossing over actually takes place, we form genetically different chromosomes. We form recombinant chromosomes. So, once again, during meiosis one, synapses between the homologous non synthetic chromatins. So let's say this one right here and this one right here takes place. And that allows the exchange of genetic information in a process known as crossing over, and that produces genetically recombinant chromosomes. So basically, during ProPhase one of meiosis, these two homologous chromosomes that have been replicated basically approach one another.