You have started your revision in earnest. Maybe you have spent some time making a lovely colour coded revision plan. Sometimes, you wake up and decide what to revise there and then.
You realise that you have two (or maybe even three!) year's worth of material to get through. You can't do that with 8 weeks left and a load of other exams to revise for.
You need a revision guide. Something that sums up everything you need to know into succinct statements.
Well, if you study AQA, they have already published their own revision guide for free - the specification.
You can find all of the science specifications for AQA GCSE here.
The specification is a document, telling you all you need to know for the exam. Some specification present these requirements in vague sentences, but not AQA, oh no.
AQA have put very detailed descriptions in their specification to the extent where some parts are the same as the mark schemes to some exam questions.
For example, here is a question from the June 2018 Biology Trilogy paper 1 (which is available in their website now!)
Describe what happens in the three stages of the cell cycle (6 marks)
The specification says this about the cell cycle:
And the mark scheme says this:
As you can see, copying out the specification is a good way to get the marks on the paper.
The mark scheme has the added advantage over any textbook or revision guide in that it never tells you too much. In fact, if you look at the statement about cell division, you can see there is a statement about what the students do not need to know.
Of course, the specification can't help with everything. It can't help with calculations for example, but it certainly can help with any process that you need to describe or explain as it basically gives you the exact phrases you need.
You can get the AQA specifications for GCSE science free from here along with past papers and other documents. I would recommend reading the Command words document and subject specific vocabulary document too.