Meiosis I: Metaphase

During metaphase, paired homologous chromosomes, which are still joined by chiasmata, align at the metaphase plate.  These pairs, consisting of four chromatids, are called bivalents.  As in mitosis, the centrosomes have migrated to opposite poles of the cell and the mitotic spindle is complete.

During metaphase, paired homologous chromosomes, which are still joined by chiasmata, align at the metaphase plate.  These pairs, consisting of four chromatids, are called bivalents.  As in mitosis, the centrosomes have migrated to opposite poles of the cell and the mitotic spindle is complete.

Microtubules of the spindle apparatus extend from the centrioles.  One set attaches to the kinetochore of the chromatids (kinetochore microtubules); one set overlaps with opposing microtubules at the midline; and a third set extends away from the spindle (astral microtubles).

During metaphase, paired homologous chromosomes, which are still joined by chiasmata, align at the metaphase plate.  These pairs, consisting of four chromatids, are called bivalents.  As in mitosis, the centrosomes have migrated to opposite poles of the cell and the mitotic spindle is complete.

During metaphase, paired homologous chromosomes, which are still joined by chiasmata, align at the metaphase plate.  These pairs, consisting of four chromatids, are called bivalents.  As in mitosis, the centrosomes have migrated to opposite poles of the cell and the mitotic spindle is complete.