AQA biology heres an amazing tip for revising it. Revise content not by spec order but by how it links to other topics. For example rather then revising protiens, enzymes, dna replication , atp etc instead revise protiens, enzymes, protien digestion, ATP synthase and hydrolase, DNAreplication etc anything with enzymes. Or lets say your gonna revise ATP, revise ATP with respiration, photosynthesis, muscle contraction etc. Dna structure, Dna replication, natural selection, inheritance, DNA gene technologies etc. I hope thats enough examples to illustrate my point.
Why do this? Because not only does it really really help with the essay when you have to link AO2 to the AO1 but also questions are formatted so that one topic will link onto another elsewhere in the spec like this year was triglycerides to lipid digestion and phospholipids and phagocytes. So revising this way is so much better and for me changed my stubborn all year C into a B and almost up to an A as i started this revision techniche a bit too late to make a huge huge difference but you, can make such a big difference