The Cell-Cycle Checkpoint That Occurs During Mitosis Causes Nuclear Division

Question

The cell-cycle checkpoint that occurs during mitosis causes nuclear division to pause until
A) DNA replication is complete.
B) sister chromatids have separated.
C) cytokinesis occurs.
D) telophase begins.
E) all chromosomes have attached to the mitotic spindle.

Accepted Answer

The checkpoint during mitosis occurs after chromosomes have lined up at the metaphase plate and before the onset of anaphase. At this checkpoint, the cell checks to make sure that all of the chromosomes have properly attached to the spindle fibers that will pull them apart during anaphase. If there are any unattached or improperly attached chromosomes, the checkpoint will cause the cell to pause in mitosis until the issue is resolved. Once all chromosomes are properly attached, the checkpoint will allow the cell to proceed to anaphase and complete nuclear division.