If you're studying for the GRE Biology test, you're going to want the guide to getting the best score you can. Research & Education Association's 'GRE Biology with CD, 6th Edition, includes proven techniques from the test-prep experts. 3 full-length practice tests with detailed explanations. 2 of the exams are on the included CD with automatic scoring. Covers all relevant GRE Biology topics. 400 pages, softcover. Sixth Edition.