Pros and Cons either way.
From the perspective of 'A' level H2 Chemistry, best options are
either :
1) Drop Pure Bio, take Pure Chem and Pure Physics.
or
2) Take Pure Chem, and drop Bio and Physics to combined
Science.
Chemistry is arguably the most important Science (in terms of
eligibility for University courses, eg. Medicine), closely
followed by Physics, then Biology as a distant 3rd
place.
Very few University courses require H2 Biology; many engineering
courses require H2 Physics; and all life-science related
courses such as Medicine require H2 Chemistry.