So one thing you need to keep in mind, is that the subjects you take do not decide what career you're going to have. Even the degree you take usually doesn't affect it that much, with the exception of engineering, clinical subjects, things like that - they set you up for a particular job. Okay, so you can't be a dentist with your A-levels, but you could go into most non-clinical jobs.
If you really want to do something "biology related" you should start off by being more specific. Do you want to be a vet? A biomedical engineer? A researcher? A doctor? A zoologist? A chiropractor?
If you plan on going to university, you should keep in mind that many biological sciences courses also require chemistry A-level, as does medicine and bioengineering (usually).
Now, for those such courses, you could take a foundation course at a university, where the first year is basically A-level catch-up on the subjects you missed. If you're still pining to do something scientific, that's my recommendation.
You could repeat a year, although my guess is that you don't want to do that.