Final answer:
The protein p53 is necessary for preventing cells with damaged DNA from replicating and dividing. It can activate apoptosis to eliminate cells with severe DNA damage.
Step-by-step explanation:
In biology, the protein p53 is necessary for preventing cells with damaged DNA from replicating and dividing. p53 acts when there is damaged DNA in cells that are undergoing the preparatory processes during the G1 phase of the cell cycle. If the DNA cannot be repaired, p53 can trigger apoptosis, or cell death, to prevent the duplication of damaged chromosomes.
For example, if a cell undergoes DNA damage from environmental factors such as UV radiation, p53 detects the damage and halts the cell cycle. It then recruits specific enzymes to repair the DNA. If the DNA damage is severe and cannot be repaired, p53 triggers apoptosis to eliminate the damaged cell.