It kind of pisses me off when people ask if they have the right A-levels to apply to so and so university, when there is tons of info about the uni's entry requirements on their website normally!
And OP- I don't think Computing bodes too well for Nat Sci, it's a bit of a random one, you would have had more of a chance doing Physics, or Computing AS instead of Biology! Give it a go and apply anyway, you've got nothing to lose.