Metaphase I

Metaphase I is similar to the metaphase of mitosis except that the paired chromosomes are aligned at the equatorial plate with one member on either side. Anaphase I and telophase I are similar to the same phases in mitosis except that the centromeres do not split and the paired chromatids, held by the centromere, remain together. A maternal or paternal member of each homologous pair, now containing exchanged segments, moves to each pole. Segregation or random assortment occurs because the maternal and paternal chromosomes of each pair are randomly aligned on one side or the other of the metaphase plate, thus contributing to genetic diversity. At the completion of meiosis I, or the reductional division, the cytoplasm divides. Each resulting daughter cell (a secondary spermatocyte or oocyte) is haploid in chromosome number (1«), containing one member of each chromosome pair, but is still diploid in DNA content (2n).

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