AQA A-level Biology Cancer HelpWatch
Do we need to know about the "two-hit hypothesis" about the tumor-suppressor genes for the new specification or is this beyond the specification? It is labelled as extension material in the AQA book, however, my teacher says you need to know it because the specification states "the role of tumour-suppressor genes and oncogenes in the development of tumours".
I would definitely learn this. It isn't complicated, and as your teacher says, this topic is in the specification, rather than purely extension work. If you want to ensure you cover everything to maximise your chances, then so some reading. You obviously need to make sure you fully understand the basic stuff about the cell cycle and how the cell is moved through it under normal circumstances. As well as looking at p53, BCL2 etc, have a look at apoptosis and its importance.