What occurs during the anaphase of mitosis?

During anaphase of mitosis, a critical event takes place where the sister chromatids, which are identical copies of a chromosome, are separated and pulled apart towards opposite poles of the cell. This separation is facilitated by structures called spindle fibers, which emerge from the centrosomes at opposite ends of the cell. Each chromatid is now considered an individual chromosome as they are pulled toward the poles, ensuring that each new daughter cell will receive an identical set of chromosomes.

This process is vital for proper cell division because it ensures that both daughter cells have the same genetic material. The accuracy of this separation is crucial because errors in this phase can lead to aneuploidy, where cells end up with an incorrect number of chromosomes, potentially leading to diseases like cancer.

The other options describe events that occur in different phases of mitosis. Chromosomes align in the cell center during metaphase, two nuclei begin to form during telophase, and the separation of cell components is not specific to a single phase but happens as part of the overall cell division process. Therefore, the description of chromatids splitting and moving to opposite poles accurately reflects the key action taking place during anaphase.