During which stage of mitosis do chromosomes line up in the center of the cell?

• A. Telophase
• B. Prophase
• C. Anaphase
• D. Metaphase

Answer: (D)

During mitosis, the stage where chromosomes line up at the center of the cell is known as metaphase. This stage follows prophase, where the chromosomes condense and become visible, and before anaphase, where the sister chromatids are pulled apart towards opposite poles of the cell.

In metaphase, the chromosomes align along the metaphase plate, an imaginary line equidistant from the two centrosomes that have migrated to opposite ends of the cell. This alignment is crucial for ensuring that each new daughter cell will receive an identical set of chromosomes during cell division. The proper orientation of the chromosomes at this stage is monitored by the spindle checkpoint, which ensures that the cell is prepared for the next phase of mitosis. This precise organization is pivotal for the chromosomal stability of the resulting daughter cells.