yeah it is... chemistry isn't too bad though, as long as you can memorise the typical answers there's a good chance of an A...
Biology on the other hand required some actual thinking... as did maths, further maths and physics... same cant be said for GS. I did them all til A-level without any problems apart from a distinct lack of social life... And it would be worth knowing that I didnt get any interviews the first time either... It's based on luck sometimes...
UCL like a non sciencey subject in there as well... so you're good with economics in the mix... cambridge require chem and 2 out of bio/phys/maths... theyre the only ones I can remember the actual entry requirements for.