Answer:
to avoid constant cell division when necessary and when not
Step-by-step explanation:
Control of the cell cycle is needed for various reasons. If the cell cycle were not regulated/controlled, cells could constantly undergo cell division over and over. While this may be beneficial to some cells (which includes cancer cells as this stage of continuous division is a favourable condition for the cells leading to the promotion of cancer (carcinogenesis)), apart from this, reproduction without cause would be biologically wasteful.
Internal regulation of the cell cycle is also important to indicate movement from one phase to the next at proper times. This regulation is not based on thorough time restriction, but rather with feedback from the cell.
Extreme regulation of this process make certain that a dividing cell's DNA is properly copied, any errors in the DNA are repaired by the repair system after a feedback mechanism, and each daughter cell receives a full set of chromosomes. This is achieved through checkpoints in each phase of the cell cycle. Two groups of proteins, called cyclins and cyclin-dependent kinases (Cdks), are involved in the progress of the cell as it undergoes this cycle through the various checkpoints there are.