Write about pachytene of prophase I.

Explanation

At this stage bivalent chromosomes are clearly visible as tetrads, Bive of meiosis I consists of 4 chromatids and 2 centromeres. Synapsis is completed recombination nodules appear at a site where crossing over takes place between non-siste Chromatids of homologous chromosome. Recombination of homologous chromosome in completed by the end of the stage but the chromosomes are linked at the sites of crossing over. This is mediated by the enzyme recombinase.