Humber Admissions Practice Test

During which phase do sister chromatids separate and move to opposite poles?

1. Anaphase

2. Telophase

3. Metaphase

4. Prophase

The correct answer is: Anaphase

Sister chromatids separate and move to opposite poles during anaphase, which is a crucial stage in cell division, specifically in both mitosis and meiosis. During this phase, the fibers of the mitotic spindle pull the sister chromatids apart. Each chromatid, now an individual chromosome, is moved toward opposite ends of the cell. This separation is vital for ensuring that each daughter cell receives an identical set of chromosomes, thereby maintaining genetic continuity. In contrast, during telophase, the chromatids have already separated and are reaching the poles. This phase involves the reformation of the nuclear envelope around each set of chromosomes. In metaphase, chromosomes are aligned at the cell's equatorial plane but have not yet separated. Prophase marks the beginning of mitosis when chromatin condenses into visible chromosomes, and the mitotic spindle begins to form, but the sister chromatids remain connected at this stage. Thus, anaphase is uniquely defined by the separation of the sister chromatids.