I definitely don't think you should be re-writing notes now. If you are still revising notes, supplement it by practising past paper questions like me.
It's fine to rewrite notes now, we still have 2 weeks till the biology exam as the HSC isn't a one week set of exams it take up to 4 weeks. If you feel like you want to consolidate your information a little further then you can rewrite notes but summarise. Even if it's just the stuff you don't know quite yet it's still a good way to review.
Not to say that past papers aren't good for study, they are, but some people need that extra bit of work before they can get stuck into their work.
Also it is best to hand write these new summary notes as you will remember it better if you write it by hand