High school biology is pathetic. Don't get me wrong, Biology is a beautiful science, but the way they teach it in the prelim course is a joke. Apparently it gets "better" in year 12 but I'm taking no chances.
EDIT: I realised that this post was unjustified, so I'll try. The syllabus is almost completely content based. There is no intellectual input required, whatsoever. In an exam, you either know the answer, or you don't. In a purer science like chemistry or even purer, physics, if you sit there thinking for about 5 seconds you can come up with the answer. So if your marks depend on your intellect, avoid biology like the plague.