Doing unit 1 tomorrow, here's what my teacher thought was likely to come up:
Parliamentary supremacy + limitations
House of Commons PLM plus supremacy
Advantages or disadvantages of Parliamentary Law Making (not both)
Judicial control (Parliamentary came up last year)
Tribunals (though I hope not, I hate them)
A scenario question with either arbitration or mediation
Not comprehensive, and quite possibly all wrong, but those are our predictions.