This helped me get through my AS exams so much, its clear, crisp diagrams made things that bit easier to understand and also the summary questions for each topic, as well as the exam-style questions at the end of each section really helped to understand what the exam will be like and give me plenty of questions to practise- sure, I didn't answer all of them, its geeky enough I'm writing a review about it, but emails from Amazon can be so persuasive...but seriously, I recommend this book to anyone who is studying the AQA AS Biology course. The A2 book's pretty much the same too!