Im pretty sure you must do Biology, I was advised to do one other science subject as well so I did Chemistry at AS-Level, I think PE or things like that count too but if you look on university sites at the entry needs to the courses you can find out more information.
e.g.
http://www.brunel.ac.uk/courses/ug/cdata/p/physiotherapybsc/fulldetails
For Brunel University it says you must get a total of 280 UCAS tariff points to include three A-levels, one must be at least a C in Biology and a C in any of the following: Chemistry, Classical Civilisations, Economics, English, Geography, History, Languages, Law, Maths, Physical Education, Physics, Politics, Psychology, Religious Education, Sociology, Sport Studies.
Hope that helps!
