Anaphase is a stage in the process of cell division, specifically during mitosis and meiosis. During this phase, the sister chromatids, which are identical copies of a chromosome, are pulled apart by the spindle fibers. This separation ensures that each new daughter cell will receive an identical set of chromosomes. As the chromatids move toward opposite poles of the cell, the cell begins to elongate. This movement is crucial for maintaining the correct number of chromosomes in each daughter cell. Anaphase is followed by telophase, where the cell prepares to complete the division process.