Prometaphase is described as which statement?

• A. Chromosomes line up in the middle of the cell
• B. The cell divides
• C. The nuclear envelope fragments and spindle microtubules attach to kinetochores of the chromosomes
• D. The chromosomes condense

Answer: (C)

Prometaphase is when the cell is actively coordinating chromosome movement with the spindle. After chromosomes condense in earlier prophase, the nuclear envelope breaks down, which lets spindle fibers interact with the chromosomes. Kinetochores at the centromeres attach to microtubules from opposite poles, so chromosomes can begin moving toward the center of the cell and align for metaphase. This description fits the statement about the nuclear envelope fragmenting and spindle microtubules attaching to kinetochores. The other options describe events from other stages: lining up in the middle is metaphase; the cell dividing refers to cytokinesis or the completion of mitosis; and chromosome condensation occurs in prophase.