I guess... but how much of it can they, practically, ask us in an exam? we're not going to be expected to implement a program to approximate a funtion using marching squares. but maybe we need to detail the process - or was that just a nifty example of some OpenGL code.
Are they going to expect us to have memorised parts of the library? e.g. "what function call would you use to change the colour of an object and how does this change when lighting is enabled?"
how about things like the first question of the first tut? some mathematical question that is completely unrelated to the subject matter: describe an algorithm for approximating a sphere (at the end of the chapter providing an overview of OpenGL).