Speaking as a former graduate student, academic honesty, especially in a graduate program, is very, very important. You could cheat and probably get away with it, but to quote the professor of a friend of mine, "you will never, ever feel good about it." As time goes by, the grade will be less and less important but the knowledge that you cheated will haunt you. And you can never tell anyone you did.

I honestly cannot imagine any of my former colleagues cheating on an exam like that. Not one of them.