Final answer:
The cell cycle is a series of events that cells go through, including growth, DNA synthesis, and cell division. It is controlled by regulatory proteins that signal the cell to start or delay the next phase. Positive and negative regulator molecules play key roles in advancing or halting the cell cycle.
Step-by-step explanation:
The cell cycle is a repeating series of events that cells go through, including growth, DNA synthesis, and cell division. It is controlled by regulatory proteins at three key checkpoints in the cycle. These proteins signal the cell to either start or delay the next phase of the cycle.
Positive regulator molecules like cyclins and cyclin-dependent kinases (Cdks) allow the cell cycle to advance to the next stage, while negative regulator molecules like tumor suppressor proteins monitor cellular conditions and can halt the cycle until specific requirements are met. When the cell cycle is no longer regulated, it can lead to the development of cancer.