Well its hard to tell what factors helped me score so high in the bio section. I studied by using my old bio textbooks (I took a lot of bio courses, which also helped), kaplan book, and then the Princeton AP Biology book. All I can say is that the kaplan book is very vague and not thorough at teaching biology (it sort of just tells you the topics you need to study but doesn't give you the actual information regarding the topics). I found that the princeton AP bio book did a good job of summarizing all the main concepts in biology clearly and concisley (which helps because the DAT doesn't test bio topics in great depth, it just covers a lot of random bio topics so you need to know them all). However, a note of caution....if you are still confused about a topic look it up in an old bio text book or Google it (if you want the easy way out, lol). Conclusion--yes, the Princeton AP bio book is awesome and you should definately use it to study for the bio section! If bio isn't your strong area, make sure you use other resources as well. Good luck!