PsychNOS is right. Still, I'm going to answer the questions for my year, assuming things aren't going to change greatly for next year (assuming the op is considering coming next year).
Typically there's one exam per block at the end of the block. For long blocks (like neuro or anatomy) there are multiple exams, like 2 or 3 in the block. Blocks range in length, but a general rule of thumb is about one comprehensive exam per month. This leads to a cycle of binging and purging knowledge, as you just slack after the exams. I prefer it this way
At least you get some sort of rest!
If an exam is failed, they often just sort of bump you through. If they want to do something about it, they'll have you write a paper or retake the exam at the end of the semester. If you retake the exam and pass, you get a grade of pass and nobody ever knows that you had to repeat the exam. The only way to fail would be to fail twice, and this very rarely happens.
Some students are more collaborative than others. It's a mixed bag, and like PsychNOS said, it's going to be the same everywhere on that one. I think there's definately an influence by H/P/F on people's habits in this area, but you can still study with friends if you want to.
I think the schedule of the first two years can be a factor, but only a minor one. There's much more important things to worry about.
Good luck!
