Final answer:
During anaphase, sister chromatids separate and the centromeres divide, allowing each pole of the cell to have a complete set of chromosomes.
Step-by-step explanation:
During anaphase of cell division, sister chromatids separate and the centromeres divide. The separation of sister chromatids is facilitated by the shortening of the spindle fibers, which act like reeling in a fish by shortening the fishing line. As a result, one sister chromatid moves to one pole of the cell, and the other sister chromatid moves to the opposite pole. By the end of anaphase, each pole of the cell contains a complete set of chromosomes.