Nope they don't assess prelim content in the hsc. Just remember topics that serve as a basis for what you need to learn in year 12: evolution by natural selection (just how it works), prokaryotic/eukaryotic cells, basic plant structure. Honestly even if you don't remember it, it will only take like 5 minutes to quickly revise it when you realise u need to know the stuff before the topic, but again its really just the very basic stuff.
For some things like adaptation, you just relearn it in year 12