Michigan Test for Teacher Certification (MTTC) Secondary Integrated Science Practice test

Which step in mitosis involves the separation of sister chromatids?

1. Prophase

2. Telophase

3. Anaphase

4. Metaphase

The correct answer is: Anaphase

The separation of sister chromatids occurs during anaphase. In this stage of mitosis, the spindle fibers shorten, pulling the sister chromatids apart towards opposite poles of the cell. This movement ensures that each new daughter cell will receive an identical set of chromosomes, contributing to the accuracy of cell division. In contrast, in prophase, the chromosomes condense and become visible, and the nuclear membrane begins to break down; there is no separation at this point. During metaphase, the chromosomes are aligned at the cell's equatorial plane, known as the metaphase plate, but they remain attached at their centromeres. Telophase follows anaphase and involves the reformation of the nuclear membrane around the separated sets of chromatids, leading to the eventual cytokinesis, but the actual separation occurs during anaphase.