INSTRUCTOR NOTE: 11th and 12th edition of Campbell Biology are both acceptable for course use. You only need one edition. Do not purchase both editions. BOOKSTORE NOTE: a 120-day access eBook for CAMPBELL BIOLOGY 12TH will be available here for $43.96 by August 26th. We recommend that you DO NOT ACCESS THE 120-DAY EBOOK UNTIL AUGUST 26TH or you may not have access through the end of the semester.