During Metaphase, what do chromosomes do?

• A. The nuclear envelope breaks up, permitting spindle interactions
• B. Chromosomes line up in the middle of the cell
• C. The cell divides into two daughter cells
• D. Chromatids separate and move to opposite poles

Answer: (B)

Metaphase is the stage where chromosomes line up along the cell’s equatorial plane, ready for separation. The spindle apparatus extends from opposite poles and attaches to kinetochores on each chromosome, pulling them into a single, orderly row at the center. This alignment ensures that when the next stage begins, the sister chromatids can be pulled apart evenly to opposite ends of the cell. The nuclear envelope has already broken down, and the actual separation of chromatids happens later, in the next stage. Cytokinesis, the division into two daughter cells, occurs after that. So, the key feature of this phase is chromosomes lining up in the middle of the cell.