(a) Synapsis:
In zygotene stage, homologous chromosomes start pairing together and this process is called synapsis
(b) Bivalent:
The complex formed by a pair of synapsed homologous chromosome is called a bivalent or a tetrad.
(c) Chiasmata:
In diplotene, the dissolution of the synaptonemal complex and the tendency of the recombined homologous chromosome of the bivalents to separate from each other except at the sites of cross overs is recognised. These X-shaped structures are called chiasmata.
