Question

pachytene of prophase 1 ????????

Answer 1

pachytene [pak´e-tēn]

in prophase of meiosis, the stage following zygotene, during which the chromosomes shorten, thicken, and separate into two sister chromatids joined at their centromeres. Paired homologous chromosomes, which were joined by synapsis, now form a tetrad of four chromatids. Where crossing over has occurred between nonsister chromatids, they are joined by X-shaped chiasmata

Answer 2

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$\red{Pachytene\: Stage: }$

⭐It is the third stage of prophase I which occurs after zygotene.

⭐ Synapsed chromosome continue to become thick and short. The chromatids of homologous chromosomes appear as tetrad.

⭐ The most important step i.e., crossing over takes place where the exchange of genetic material between the non-sister chromatids of the homologous chromosomes occurs.

⭐ An enzyme-mediated process called recombination takes place. An enzyme recombinase is involved during this phase.

⭐ By the end of pachytene, the recombination between the homologous chromosome is complete and the two chromatids are linked at the site of crossing over.