I do a level bio. Just sitting my last exams for it now. Honest opinion - I struggle bad with it. At GCSE I achieve an A* in Maths, 9As and a C in Drama, all my sciences were an A. Biology is just so content heavy and the paper s 70% application, 10% maths and 20% content recall. The maths I cannot do at all and I got an A* at GCSE, its completely different applying it to another subject. If you really need biology to do your chosen career then go for it, work hard and honestly do not leave revision to last minute, keep going throughout the year because thats the only way you will pass biology. My grades vary from an A* in a level bio to a U... its very difficult.