Botany - Cell Cycle and Cell Division Question with Solution | TestHub

Checkpoints are internal controlling mechanisms in the cell cycle. Due to these checkpoints, the cell cycle is monitored at various stages. There are three major checkpoints seen. The first is as the${\mathrm{G}}_1$phase ends. Second is when${\mathrm{G}}_2$ends and the cell is about to enter the Mitotic phase. The third is during the metaphase.

The first checkpoint checks whether the conditions are suitable for cell division to place or not. If the conditions are not proper the cell will be arrested and will enter the${\mathrm{G}}_0$phase instead of the${\mathrm{G}}_2$phase. The second checkpoint is at G2-M interphase. Before the cell enters the M phase the cell is checked at this point. This ensures whether all the chromosomes in the cell are duplicated or not. It also checks that the DNA which is replicated is not damaged. The third checkpoint is at the end of Metaphase and this is also known as spindle checkpoint as it checks whether all the chromatids are connected to spindle fibres or not.