Why do the Snake River plain and the emperor seamounts trend in the direction that they do?

Have you asked your teacher about any of these questions? A TA? Other students? I assume that this is a college course, and college professors hold office hours for a reason, go and ask him/her. If that doesn’t work for you try the TA if you have one, they can often explain things in a different way than the professor, which may help. If your wording of this question is a direct quote from the study guide, then it is pretty enigmatic. Just going over the wikipedia entries the one thing they have in common is the movement of a tectonic plate along a volcanic hotspot. But I’ve no idea if that is what your teacher is looking for, and I’m a geographer, not a geologist, so we’re often a little shady on the really technical stuff.