Go see your tutor, but first try to work out why you aren't connecting with the subject. Nothing worse than turning up and having nothing to say. I know I loved mammalian cell biology and found botany so dull. if its a modular course see what modules you can do next and if they sound good it might be worth sticking it out. If not you could look into transferring to a more specific course eg molecular biology, pharmacology, biomedical, biochemistry, botany, physiology etc etc... Also are enjoying university in general? You might be blaming your course for other problems and not realising it. Only say this because you loved the subject at A level and first year tends to be a re-cap.