What if you've never sat through a physics or chemistry class?

<p>In my high-school, during freshman year we were to decide wheather we wanted to join the "Arts'' class or the "Sciences" class. I joined the arts class, were we take extensive courses in history and english as well as moderate courses in biology and maths inadditional to a few more additional subjects. However; most people in our school agree that the science class is more challenging since they take more courses and since the english course is nearly the same for both classes.
The other day I was looking through some Ivy league college websites and it said that it is important to have completed a year of physics and a year of chemistry.
I just sat there staring at the page and wondered if this was were I was to kiss my harvard dream goodbye...
But wait- does it really matter to the admissions office if I never sat through a chemistry or physics class before? even if I've taken challenging courses in the "Arts' section?
I was thinking if it does matter then maybe I should study alone to take the chemistry and physics olevel or SATII exams....is that a good idea??
Also my school is in Dubai, so do you think the admissions' will take into account that as an international student in a school as such they may somehow still accept me?</p>