A-level biology

[confused_x]

Hi, I need an A level in biology in order to go to university and study physiotherapy. The problem is I have already started my A levels I'm 17 and in my first year of 6th form, I have taken, eng lit, psychology, pe, and business. My options to take biology are, night school, home learning, staying on at my 6th form for an extra year (which messes up my gap year I wanted to take) or try and complete the A level in one year (next year) This has really got me I am interested in any information anybody has on the subject. Advice on what to do and how to go about it would be brilliant.

Thank you