Here's a list of the bio classes I took as an undergrad:
Freshman year - Ecology and Evolution (only helpful thing was the freaking Hardy-Weinberg equation....I probably spelled it wrong too...shows how important it was) Funny enough, it does actually come up again when you get into medical school and take Epidemiology/biostats
Sophomore year - Genetics, Biochemistry, and Molecular Biology...(I took the MCAT in April of 05, which was the paper version back then, but now it's all computerized...) I've been told by many of my younger friends that there was much more of an emphasis on Molecular biology/molecular genetics. Biochemistry...I don't remember a single question about glycolysis...etc.
Junior year - Physiology, Neuroscience, Microbiology, - i would say physio helped A LOT. At least when I took the MCAT there was a huge amt of Physio. I had questions where I'd be given a set of data valves for patients treated with ADH, they then collected urine samples and asked us to make conclusions about the person. Neuroscience wasn't heavily tested if at all...I seriously can't remember. But Physio helps for sure. Microbiology i took for my major and although it's not tested on the MCATs, its pretty helpful for medical school.
senior year - cell biology, immunology, anatomy. I had already taken my MCATs by that time, but I'd say immunology was slightly helpful. I think I had one passage or something that required a little bit of immuno info...but it wasn't super hard. Cell biology would have been somewhat helpful. I remember I had a couple of questions about signal transduction (cAMP or something like that rather). There's not really any anatomy on the MCAT.
I didn't take any prep course and sorta studied on my own but in talking to my friends who took a prep course, I'd say if you take the regular classes youre supposed to take and then do a prep course, you'll get all the info you need for your MCATs. Pretty much all my friends and I scored 30+.
In terms of Medical school...and this is only if you have a real interest and some time...many of the things you see as an undergrad show up again. For instance, you'll have to relearn all of biochemistry again (all the cycles and pathways..etc). You'll see transcription, translation all over again (all the factors and whatnot). Immunology was REALLY helpful because the second time through in med school was a lot easier. The physiology course I had as an undergrad really helped as well. I'm taking med phys right now and it's actually very similar to what I learned in undergrad (granted I also took physiology lab which definitely helped solidify many of the concepts and formulas).
Other classes that some of my undergrad friends took and said were helpful were Parasitology, Infectious Diseases, and Intro to Pathophysiology. I don't know if your school offers those courses, but they're certainly helpful for when you get into medical school.
Good luck with everything
