During this phase of mitosis, the spindle microtubules contract and pull apart the daughter chromatids one to each pole of the cell.

During mitosis, the phase in which spindle microtubules contract and pull apart the daughter chromatids toward opposite poles of the cell is known as anaphase. During this critical stage, the connections that hold the sister chromatids together at the centromeres are severed, allowing them to move independently. As the spindle fibers shorten, they effectively tug the chromatids apart, ensuring each new daughter cell will receive an identical set of chromosomes when the cell divides.

In contrast, during prophase, the chromatin condenses into visible chromosomes, and the mitotic spindle begins to form, but the chromatids remain connected. During metaphase, chromosomes align at the cell’s equator, with spindle fibers attaching to the centromeres, but they have not yet begun to separate. In telophase, the separated chromatids have already moved to the poles, and the cell begins to de-condense the chromosomes back into chromatin and reform the nuclear envelope, marking the end stages of mitosis. Therefore, anaphase is distinctly defined by the separation and movement of chromatids, making it the correct answer.