Which stage of mitosis involves the chromosomes separating and moving toward opposite poles?

In mitosis, the stage where chromosomes separate and move toward opposite poles is known as anaphase. During this stage, the sister chromatids, which were previously aligned at the metaphase plate, are pulled apart by the spindle fibers attached to the centromeres. The separation occurs as the proteins that hold the sister chromatids together are cleaved, allowing each chromatid to become an individual chromosome.

As the chromosomes are pulled toward opposite ends of the cell, this ensures that each new daughter cell will receive an identical set of chromosomes. This movement is crucial for the accurate distribution of genetic material during cell division, which ultimately contributes to the maintenance of genetic stability.

In contrast, during prophase, the chromosomes condense and become visible, but they are not yet aligned or separated. In metaphase, the chromosomes are lined up at the center of the cell, preparing for separation. Finally, in telophase, the chromosomes reach the opposite poles, and the nuclear envelope re-forms around each set of chromosomes, but the actual separation has already occurred in anaphase.