Pre-req and what needs to be done when

You are not required to have your prerequisites complete until you matriculate at your medical school. It's probably a good idea to finish them before you take the MCAT, though, unless you can teach yourself the material. It is fine if you complete Physics II after you've submitted your Primary application for med school.

 

Have your prereqs completed BEFORE taking the MCAT. This seems like common sense, but a lot of students don't. Other than that, no worries.

 

I didn't have several of my prereqs done before taking my MCAT or applying. It hasn't been a problem for either (35+ on the test, interviews at several top ten schools). It really depends on your background. If you know that you're a good standardized test taker (e.g., you scored more than 700 on each section of your SATs) and if you have good background from high school in the topics you haven't covered, it shouldn't really be a problem given sufficient time to study for the MCAT. If you decide to use materials from one of the big test prep companies (Kaplan, Princeton Review, Examcrackers) they'll give you everything you need to get above a 35, even if it's been a while since you've seen the material. I know some people who put off applying for a year or took a dangerously late MCAT to accommodate their prereq schedule. In my opinion, this is silly.