In Prometaphase, what happens?

• A. The nuclear envelope fragments and spindle microtubules attach to kinetochores of the chromosomes
• B. Interphase occurs
• C. Cytokinesis completes
• D. Chromosomes condense at the metaphase plate

Answer: (A)

Prometaphase is about the start of chromosome movement as the cell prepares to align them. The nuclear envelope breaks down, so spindle microtubules can interact with kinetochores on the chromosomes. These kinetochores grab onto the microtubules from opposite poles, pulling the chromosomes toward the center of the cell and beginning their distinct movements. The chromosomes are already condensed by this point, a process completed earlier in prophase, so condensation isn’t what happens here. Interphase happens before mitosis, and cytokinesis occurs later after mitosis is finished.