The tumor suppressor gene p 53 induces cell cycle arrest at

Ref Robbins 8/e p290-291 ,9/e p294 The cell cycle has its own internal controls called checkpoint, there are two main checkpoints ,one at the G2/S transition and another at G2/M In the G1/S checkpoint ,cell cycle arrest is mostly mediated through p53, which induces the cell cycle inhibitor p21 Arrest of the cell cycle by the G2/M checkpoint involves both p53 dependant mechanism As can be deduced from above mentioned information that the p53 is associated with both the types of checkpoint , however G2 /M checkpoint can take place even without p53.hence option" C" is the preferred anwers