Throughout the cell cycle, there are numerous checkpoints, or proofreading stops. These checkpoints are extremely beneficial for
making sure the intricate steps of growth, repair, and replication are being performed correctly. Why do you think the cell would need these checkpoints? What do you think would happen if the cell did not get checked at certain phases?
Cells need checkpoints to ensure that no error is present in the DNA or even in the cellular surroundings. It is critical that all "boxes" are checked before continuing because this ensures that no major errors are faced down the line. Cells are basic unit of life so if cells are not accurate or full of errors then tissues are affected, which affects organs, and eventually organ system and in final the whole organism. Thus, checkpoints ensure that errors are caught early and dealt with properly.
If cell did not get checked at certain phases, mistakes would go by unnoticed which could affect the whole organism (see my explaination above). Also, checkpoints ensure that cell growth is controlled (that is unwanted replication do not occur). If there are no checkpoints then cell can continue to grow and eventually uncontrolled growth of cells is referred to as cancer.
Basically no one knows that an earthquake is coming until it's happening. People don't have time to evacuate because they don't know that an earthquake is going to take place , in other words the earthquake takes them by surprise.
