It's just the basis for you to recite the difference between realism and liberalism, as it was taught in your class.
Actually, just think of every question for every exam in the course as really saying "show us you were paying attention, that you understand, and that you can use the language we introduced."
This is ultra important and I'm hitting myself for not phrasing it more like this, but I was totally watching something at the same time and it's like INTRO so...plus there were cat videos and like...
Anyway, yeah, this is important even at higher levels of any field. If you can show you get THE FUCKING POINTS you won't ever have major issues since that probably means you're smart enough to reason out the other aspects of the question. (And even on into 700+ levels you'll be shocked at how people don't get things that are seemingly simple concepts.)
I always hate when students fail horribly at application questions not because of lack of information, and it might be because that's how I've always approached everything, but I hate when someone writes like six pages just reciting every single theory or reference or whatever the fuck. You CAN generally do as well or better at getting around the "minimum" if you just ANSWER the question. Like the "nationalism" question, I don't know what was discussed in class, the text, etc. but I could see someone writing a good argument for that outside of any of that, so know your argument and apply it, if you don't cite this jerk or that stupid theory, that's fine if you get the key points. Especially the ones discussed in class. (Usually: A professor/teacher/etc. saying something > any textbook. Even if one or both are wrong. Plus, they like when you get to the point instead of having to read gibberish.)
If I gave you these questions I'd be looking for that you got those basic points, that you could describe the realist/liberal divide, that you could explain the basics of international relations and that you could make a sound argument in some manner for or against nationalism. (Not a fan of that question, I assume it's a "research interest" of the prof.) Now if you couldn't tie any of this to your opinion on say terrorism or currency or whatever that's different. As I poorly tried to explain, the opening questions are so that you can frame the course content into your own perspeective. So like in my example, if you were big on terrorism, you could go and apply the realist/liberal divide to this issue that you knew and thus could write something that made sense.
One thing I always tell students and well anyone is that, apply it to something YOU KNOW. In Poli Sci especially there are ways to tie it to whatever your thing is, war on terror, war on drugs, abortion, gay marriage, tax rates, whatever floats your boat, you can apply most anything to these kind of theories/ideas to help understand it. There are always differences but the basic concepts are pretty easy to move from thing to thing. Then you just have to add the detail really.