Aetna CEO: Obamacare In A 'Death Spiral' Heading Into 2018. Aetna and Humana have called off their deal amid government concerns over competition. Here's a look back at six pivotal moments that led to this. Aetna and Humana have called off their deal amid government concerns over competition.
For the plant genus, see Synapsis (plant). Synapsis (also called syndesis) is the pairing of two homologous chromosomes that occurs during meiosis. It allows matching-up of homologous pairs prior to their segregation, and possible chromosomal crossover between them. Synapsis takes place during prophase I of meiosis.
The crossing over of the chromosomes. Synapsis of Homologous chromosomes does not occur in Mitosis. In Meiosis, occurs during Prophase I along with crossing over between non sâ¦ister chromatids; resulting chiasmata hold pairs together due to sister chromatid cohesion.