Hold on a second, cell's checkin' Cyclin levels risin, CDKs connectin! Checkpoint in G, gotta verify, If the DNA is damaged then the cell won't comply. p53 on the scene like a guardian knight, Halts replication when the sequence isn't right. Regulate it- From the genome to the lembrane, signals orchestrated. Regulate it— Rb holds E2F back 'til the path is validated. Division's complicated- But every step is perfectly coordinated. Cell fate dictated- Yeah, life is always tightly regulated. Cyclin A with CDK2 keeps S-phase flowin, Helicase unwinds DNA, replication goin. p21 steps in when the stress is high, Stops polymerase until repairs can apply. Apoptosis primed when the signals misalign, Bax and Bak open channels in the mitochondria line. Cytochrome c released, caspase cascade engaged, Cell dismantles safely when the program's staged. Regulate it- Growth factors tell the cell which route is designated. Regulate it- MAPK talks to genes till the plan is activated. Cycle moderated- Errors caught before they're replicated. Organism celebrated- 'Cause every cell is tightly regulated.