Final answer:
The cell cycle is controlled by checkpoints, which ensure the cell is ready to proceed with cell division. There are three major checkpoints: G1, G2/M, and metaphase. They utilize regulator molecules like cyclins and Cdks to advance the cell cycle, or halt it if conditions are not met.
Step-by-step explanation:
The cell cycle is controlled by specific steps called checkpoints, which can delay progression to the next stage unless certain conditions are met. These checkpoints serve as critical quality control mechanisms that ensure the integrity of the cell's DNA and other cellular components before it proceeds to the next phase of the cycle.
There are three major checkpoints in the cell cycle: one near the end of G₁, a second at the G₂/M transition, and the third during metaphase. Positive regulator molecules, including cyclins and cyclin-dependent kinases (Cdks), enable the cell cycle to advance to the next stage. On the other hand, negative regulator molecules act as internal monitoring systems that can halt the cycle if the cell is not in proper condition, ensuring only healthy cells proceed with division.
To prevent compromised cells from continuing to divide and potentially passing on mutations, these checkpoints play a pivotal role in maintaining cellular health and preventing conditions such as cancer, which is characterized by uncontrolled cell division due to faulty regulation of the cell cycle.