Both Biology101.org and SparkNotes.com have study guides for life sciences, also called biology, as well as other tools such as flash cards. SparkNotes offers its study guide in the form of a set of categorized pages on various biology subjects, while Biology101 has a general list of specific studying topics.
Some websites offer differing levels of biology study. For instance, the College of DuPage offers more comprehensive lessons in basic biology than what is found in a high school format. Other resources such as Shmoop.com require an account or a subscription in order to access more advanced study tools, such as AP or SAT tests, or full courses on biology.