Maths student cannot be a Doctor???

I want to study Medicine in U, but it usually accept Biology Stream student (AL Phys, Chem, Bio). if I take Bio Stream, and AL result not A A B. Medicine will not accept.
Bio student with fair result usually study Bio-Chemistry in U???

If I take Maths stream (AL Pure Maths, Chem, Phys) will be more professional subjects can take in U.

Does any case study Pure Maths, Phys, Chem can became a doctor?

I don't want if cannot study Medicine, just study some general subject in U.