Explain what happens at the first checkpoint
If GO is prevented from occuring.
Answer: these cells can be called back from the G0 phase to the cell cycle by external cues
G1 checkpoint mechanism ensures that the cell is ready for cell division
Is this what happens if the GO phase is prevented from occuring?
Really couldn't find an answer that I was for sure about
To understand what happens at the first checkpoint in the cell cycle, it's important to know that cells progress through a series of phases in order to divide and reproduce. The first checkpoint, also known as the G1 checkpoint, occurs at the end of the G1 phase, before the cell enters the S phase where DNA replication takes place.
At this checkpoint, the cell undergoes a set of checks to ensure that the conditions are appropriate for DNA synthesis and cell division. The main purpose of this checkpoint is to prevent the cell from progressing further into the cell cycle if it is not ready or if there are any abnormalities detected.
If GO (the progression from G1 to S phase) is prevented from occurring due to external cues or signals, it means that the cell is temporarily arrested in the G0 phase. The G0 phase is a non-dividing state where cells can either enter a resting state or differentiate into specialized cell types.
However, even if the cell is in the G0 phase, it can be signaled or called back to re-enter the cell cycle by external cues. These cues could be growth factors or signals indicating that the environment is conducive for cell division. Once the appropriate conditions are met, the cell can move forward through the G1 checkpoint and reinitiate the cell cycle by entering the S phase for DNA replication.
In summary, if GO is prevented from occurring, cells can be called back from the G0 phase to the cell cycle by external cues, allowing them to progress through the cell cycle and eventually divide.