This book is excellent and is a must-buy for the more able (A-B standard) biologists whose schools/colleges only give them the OCR biology 2. It is more detailed and comprehensive.
The only criticism is that it is called "Essential A2 Biology for OCR" and yet it DOESN'T cover the whole of the OCR A2 syllabus - only one module! I understand that it won't have a module 5 section, because this module has 5 options and it would be too much to write for each one.
However, it should have a section at the end on module 6! just a synoptic chapter on what it's about, topic overlaps, how to answer the questions, practice questions etc.
But it is still worth buying for the Central Concepts module, especially if you want to get an A!