Final answer:
The checkpoint(s) a cell uses to determine if it can move on to the next stage of division is primarily the G1 Checkpoint, where the cell assesses conditions for division, influenced by growth factors and regulated by cyclins and Cdks.
Step-by-step explanation:
Checkpoint(s) are critical regulatory points in a cell's cycle where the cell evaluates whether it is ready to move onto the next stage of division. The G1 Checkpoint, one of the major checkpoints, assesses if conditions are favorable for cell division, including adequate reserves, proper cell size, and undamaged genomic DNA. When a cell reaches the G1 Checkpoint, also known as the restriction point, it irreversibly commits to the cell division process if all requirements are met. External factors such as growth factors influence the cell's progression past this checkpoint.
Cells that meet all the criteria at the G1 checkpoint are allowed to enter the S phase, where DNA synthesis takes place. If the required conditions are not fulfilled, the cell may either halt the cycle to fix any issues or enter a quiescent state (G0) until conditions improve. Internal molecular signals like cyclins and cyclin-dependent kinases (Cdks) regulate cell cycle transitions and work alongside checkpoint controls to manage cell cycle progression efficiently, playing a critical role in preventing errors that may lead to uncontrolled cell division, such as cancer.