Well, in the version I dream of there are the rules, the normal punishments, the corporate punishments and there is no expulsion

If not maybe for extremely serious offenses.

And obviously it's all adults

As a side note, I don't think the kids they cast for this show are among the brightest/most studious ones. For sure they represent a part of the population but they're nor representative of the most of it (hopefully). Also I haven't watched the british version, so I'll admit I have no idea if there are fundamental differences...