Professor Elm embodies that professor who is working on way too much stuff to actually care about what you're up to. This guy is currently going over research that is so much more important than your midterm to him, all he can do is give you an assignment and hope to god you'll complete it. If you do help him out with his research, he'll probably claim all the credit.
This guy is all over the place, you can just tell by his outfit. That lab coat is fooling no one. He's basically another student, but somehow is allowed to teach you because he's already graduated from undergrad. Basically, he'll give you credit for saving his ass on his own assignments.
This is that one professor who is perfect for you, mainly because she's just the school version of your mom. Her class is your favorite, and you never want to stop having class with her. Her comments are always supportive, and she's happy to see you succeed. You will only ever see one class with her, and you'll miss it. So much.
This is that professor who is a genius in his field and comes with an attitude and most probably an accent. However, as you spend more time with him, you discover that he's not mean, he's just foreign, and he probably has a stash of candy in his office he'll share with you! More realistically, he has booze.
This guy's job is so safe, he doesn't give a fuck anymore. Chances are, even if you take a class with him, he won't recognize you. Are you a boy or a girl? What's your name again? He cares so little he doesn't even remember his relative's names. He'll be in your school longer than anybody else. Get used to him.