Meiosis - Meiosis Interphase Chromosomes replicate during S...

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Meiosis Interphase Chromosomes replicate during S phase but remain uncondensed each replicated chromosome consists of 2 genetically identical sister chromatids connected at the centromere the centrosome replicates, forming 2 centrosomes Prophase I longest phase – 90% of time required for meiosis chromosomes begin to condense homologous chromosomes (homologues) pair along their lengths, precisely aligned gene by gene crossing over: DNA molecules in nonsister chromotatids break at corresponding places and then rejoin to the other’s DNA synapsis: synaptonemal complex (a protein structure) forms between homologues, holding them tightly together along their lengths synaptonemal complex disassembles in late prophase, and each chromosome pair becomes visible in the microscope as a tetrad (4 chromatids) each tetrad has 1+ chiasmata, criss-crossed regions where crossing over has occurred; these hold the homologues together until anaphase I
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movement of centrosomes, formation of
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Meiosis - Meiosis Interphase Chromosomes replicate during S...

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