Checkpoints are like security guards for cells. They make sure everything is running smoothly before a cell divides. These checkpoints are super important because they help keep cells healthy and ready to move on to the next stage. Let’s explain this in a simpler way:

The Three Major Checkpoints

1. G1 Checkpoint:

   • This happens at the end of the G1 phase.
   • The cell checks for any damage to its DNA and makes sure it has enough resources to grow.
   • If something is wrong, the cell can stop and try to fix it. Sometimes, it might even decide to self-destruct.

2. G2 Checkpoint:

   • This takes place after the DNA has been copied.
   • The cell checks again for DNA damage and sees if the copying went well.
   • If everything is okay, the cell moves on to the next stage called mitosis.

3. M Checkpoint:

   • This happens during mitosis.
   • The cell makes sure that all the chromosomes are properly attached to the spindle fibers before dividing.
   • This helps prevent problems with how the genetic material is shared.

Why Are Checkpoints Important?

These checkpoints help stop mistakes that could lead to cancer or other illnesses. You can think of them as important quality control steps in a cell's life. They make sure everything is working properly before the cell moves forward!