Final answer:
During anaphase, sister chromatids separate and move to opposite sides of the cell. This phase is facilitated by the shortening of spindle fibers. Telophase follows, where chromosomes reach the opposite poles and start to decondense.
Step-by-step explanation:
Anaphase is the phase of cell division in which sister chromatids separate and move to opposite sides of the cell. During anaphase, the centromeres divide and the sister chromatids are pulled apart by the shortening of the spindle fibers. One sister chromatid moves to one pole of the cell, while the other moves to the opposite pole. At the end of anaphase, each pole of the cell has a complete set of chromosomes.
In telophase, the chromosomes reach the opposite poles and begin to decondense, unraveling into a stretched-out chromatin configuration. The mitotic spindles are depolymerized into tubulin monomers. Nuclear envelopes form around the chromosomes, and nucleosomes appear within the nuclear area.