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

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

Answer: (A)

The stage where chromosomes line up along the center of the cell is metaphase. In this phase, the chromosomes have condensed and become visible, the spindle apparatus forms, and kinetochores attach to microtubules from opposite poles. The chromosomes align along the metaphase plate, an imaginary plane midway between the two poles, with sister chromatids held at their centromeres. This precise alignment ensures equal separation when the chromatids are pulled apart in the next stage. Earlier (prophase) the chromosomes condense; later (anaphase) the chromatids separate and move to opposite poles; and later (telophase) the chromosomes arrive at the poles and de-condense as the cell proceeds to cytokinesis.