Honestly; if you're in uni and pass your degree and don't plan on teaching Biology as a career or something else where a really high A level Biology grade is going to be needed, its probably best to just focus on enjoying your first year at uni and putting the work in to get the best degree classification possible at the end. 99% of employers only care about your highest qualification anyway, so probably won't be too annoyed by one blip in what sounds like an otherwise great set of A Level grades and alongside a university degree. In my opinion, you're best saving your time and sanity!