what is synapsis in meiosis

Synapsis is the process of pairing of two homologous chromosomes that occurs during meiosis. It mainly occurs during prophase I of meiosis I. During synapsis, the ends of homologous chromosomes are first attached to the nuclear envelope, and then they migrate until matching ends have been paired. The intervening regions of the chromosome are brought together, and may be connected by a protein-RNA complex called the synaptonemal complex. The central function of synapsis is to identify homologous chromosomes by pairing, which is an essential step for a successful meiosis. The processes of DNA repair and chiasma formation that take place following synapsis have consequences at many levels, from cellular survival through to impacts upon evolution itself. The synapsis of homologous chromosomes has a couple of different functions in organisms. First, it holds the homologous chromosomes together through metaphase I of meiosis I, which allows them to be aligned on the metaphase plate and separated. This is a key task during meiosis, as this is how the genetic information in each gamete is reduced. Secondly, it allows for the exchange of genetic information between homologous chromosomes, which is known as crossing over.