I pretty much re-read all of Cambell's Biology book (7th Edition), except the chapters on plants (like Chapters 31, 32, 33 etc..) and the ecology chapters (like Ch. 51,52,53, etc). I also skipped other longer, more detailed chapters that I felt were out of the scope of the DAT like Chapters 11, 19, 20, 21.
Just by reading Cambell's alone, I got a 22. I don't think Kaplan's Bio is sufficient enough.