Some unis will accept that, but some will not. Some may accept it but consider you less competitive.
Note quite a lot of bioscience degrees prefer or require a second science A-level. Some specifically require A-level Chemistry (as it underpins the modern biosciences).
With only 1 A level, you will need to look at mostly 'UCAS points' Unis and check that they will accept, probably by emailing them, as A level / BTEC combos can sometimes get complicated.
Plymouth as one example wants "A level Biology and a second relevant subject (Mathematics, Physics, Chemistry, Geography, Geology, Environmental Science or Environmental Studies, Applied Science, Marine Science)." and it isnt clear if they would accept a science related BTEC for the second science. However they also offer a Foundation Year for those without the right quals/subjects etc - BSc (Hons) Biological Sciences with Foundation Year - University of Plymouth