WesternU/COMP
Your grades in classes are at least 95% of your grade. The other 5% are minor projects like Group Presentations, Evidence Based Medicine Literature Review, Clinical Case Scenario Questions. These projects are only a minor part of your grade and not every system has them, but you have to participate in the projects to pass the course.
As far as what its like at a DO school, I can only speak for COMP, but its probably very similar at other schools.
You're first semester you complete all you basic science courses: Physiology, Pathology, Biochemistry, Pharmacology, Gross Anatomy, etc. and you won't really have any projects. At COMP there is pretty much an exam every Monday during your first semester. You will spend about 10 hours(minimum schedule class time) in the Gross Anatomy Lab. Many people spend extra time on their own, but this is the time alotted on the schedule. Tuesdays and Wednesdays are typically OMM days, and you'll spend the majority of the morning in the OMM lab. It is a nice change from just sitting in class in a lecture hall. Of course 1/2 of your anatomy grade is based on lab, where you have to identify tagged structures....just like the movie Gross Anatomy if you've seen it.
After the first semester, you'll start in on the Systems, where you learn about each system, with much more clinical information, and you expand a lot on the basic science information from the first semester.
At COMP the systems are arranged in this order: (this is after your first semester of your first year which is the basic sciences)
Second Semester, First Year:
Dermatology
Neurosensory
Musculoskeletal
(During this semester you'll also have one week called ICM - Intro to Clinical Medicine, where you learn how to do History and Physical Exams, and some basic procedures at the clinic, i.e. blood draws, EKG, Vital Signs, etc. There is also a week of Behavior Medicine after the Neurosensory System)
First Semester, Second Year:
Blood and RE System
Cardiovascular System
Respiratory System
(Psychiatry is blended in the Cardiovascular System, you'll have lectures every Friday on Psych) There are a couple of projects in Psych, which are actually pretty mundane and waste of time in most peoples opinions....but, you just gotta suck it up and finish it
Second Semester, Second Year:
Renal System
Endocrine
Reproductive System
Gastrointestinal System
Its a lot better once you get through the first semester of med school, because once you start the systems, you don't have a test every Monday. They are every few weeks....which is nice.
During the entire first two years you'll have practical exams in OMM, where you have to demonstrate techniques, etc. There are two a semester, a mid-term practical and a final, and the information is cummulative. Techniques that you learn the first semester will be built upon and you'll be responsible for those techniques for the entire first two years. At the end of each semester, there is a written final exam on OMM.
This is what to expect at a DO school, specifically COMP....hope it helps.