What occurs during Anaphase of mitosis?

During Anaphase of mitosis, the key event is the division of the centromeres, which allows the sister chromatids to be separated and pulled apart to opposite poles of the cell. This separation is crucial because it ensures that each daughter cell receives an identical set of chromosomes, maintaining the genetic integrity of the organism. As the chromatids separate, they are guided by the spindle fibers toward the poles, which facilitates their eventual distribution into the two new cells that will form following the completion of mitosis.

In contrast, the other options describe different stages of mitosis or cellular processes. The alignment of chromosomes at the equatorial plane occurs during Metaphase, the reformation of the nuclear envelope happens during Telophase, and DNA replication takes place during the S phase of interphase, before mitosis even begins. Understanding these distinctions helps clarify the specific events that characterize Anaphase within the broader context of the cell cycle.