That's weird...the reply is posted above the question.
Normally I'd say ignore scaling, since it's useless in real terms (your raw marks and rankings make all the difference). Which are you more interested in? Biology is pretty handy in med, but most people going in have the Chemistry/Physics/Maths conglomerate instead so they just assume you don't know any biology.
I guess what I'm saying is if you like history more, and can keep up the marks, stick with it and aim for the bullseye.