G1 checkpoint

The G1 checkpoint is a critical control point during the cell cycle, specifically before a cell enters the DNA-synthesis phase (S phase). It ensures the cell is ready to divide by checking for proper size, nutrient availability, and DNA integrity. If conditions are favorable, the cell proceeds to replicate its DNA; if not, it may delay division or enter a resting state. This checkpoint helps prevent damaged cells from dividing, which is crucial for maintaining healthy growth and function in living organisms. Essentially, it acts like a quality control system before a cell commits to division.