Chiasma (genetics)
You don't need to be Editor-In-Chief to add or edit content to WikiDoc. You can begin to add to or edit text on this WikiDoc page by clicking on the edit button at the top of this page. Next enter or edit the information that you would like to appear here. Once you are done editing, scroll down and click the Save page button at the bottom of the page.
A chiasma (plural: chiasmata), in genetics, is thought to be the point where two homologous chromatids exchange genetic material during chromosomal crossover during meiosis (sister chromatids also form chiasmata between each other, but because their genetic material is identical, it does not cause any change in the resulting daughter cells). The chiasmata become visible during the diplotene stage of prophase I of meiosis, but the actual "crossing-over" of genetic material is thought to occur during the previous pachytene stage. When each bivalent, which is composed of two pairs of sister chromatids, begins to split, the only points of contact are at the chiasmata.
- chiasma frequency = 2 x recombination frequency
where recombination frequency is:
- recombination frequency = (no. of recombinants) / (total no. of progeny)

