During which stage of meiosis do homologous chromosomes separate?
During which stage of meiosis do homologous chromosomes separate?
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Homologous chromosomes separate during Anaphase I of meiosis. This stage is critical as it marks the point where the homologous pairs, which have been aligned at the metaphase plate during Metaphase I, are pulled apart to opposite poles of the cell.
Key Points about Anaphase I:
- Separation of Homologous Chromosomes: In Anaphase I, the spindle fibers pull the homologous chromosomes apart, ensuring that each daughter cell will receive one chromosome from each pair. Importantly, the sister chromatids remain attached at their centromeres during this stage.
- Mechanism: The separation occurs due to the action of microtubules that are part of the spindle apparatus. These microtubules attach to the kinetochores of the homologous chromosomes and pull them toward opposite poles.
- Outcome: After Anaphase I, each resulting daughter cell will have half the number of chromosomes, each consisting of two sister chromatids. This reduction is essential for maintaining the correct chromosome number in gametes after meiosis II.