Bio is alright cos I'm doing is a load of the essay questions and that helps me with both the essay skills and knowing my stuff. You go through stuff quite well doing them. As for chemistry, I have no clue how I'm gonna do that!!
i have 3 synoptic papers, all sciences and chemistry is by far the scariest, at least biology, you can just make some random stuff and remember some other stuff you've learnt at AS/A2, and in physics you can get marks by doing some equations, maybe even plotting graphs, not sure, but in chemistry, you even LEARN HOW TO DO THE CALCULATIONS! my god, i hate it!!