Question

match each checkpoint with the action it checks for.
g₂ checkpoint
m checkpoint
g₁ checkpoint
checks whether the microtubules have attached to the centromeres of the chromosomes
checks for cell size and dna damage
checks whether dna has doubled and repairs it if damaged

Explanation:

• G₁ checkpoint: This checkpoint occurs at the end of the G₁ phase. Its main role is to check if the cell has reached an appropriate size and if there is any DNA damage. If the cell is of adequate size and there is no DNA damage, it can proceed to the S phase (synthesis phase) where DNA replication occurs.
• G₂ checkpoint: It is located at the end of the G₂ phase. The G₂ checkpoint verifies whether DNA has been properly replicated (doubled) and if there is any DNA damage. If the DNA is correctly replicated and undamaged, the cell can move on to the M phase (mitosis phase).
• M checkpoint: Also known as the spindle - assembly checkpoint, it takes place during the M phase (specifically in metaphase). The M checkpoint checks whether the microtubules have attached to the centromeres of the chromosomes. This is crucial for the proper segregation of chromosomes during anaphase.

Answer:

• G₁ checkpoint: checks for cell size and DNA damage.
• G₂ checkpoint: checks whether DNA has doubled and repairs it if damaged.
• M checkpoint: checks whether the microtubules have attached to the centromeres of the chromosomes.