Essential knowledge 3.A.1: DNA, and in some cases RNA, is the primary source of heritable information. Probably the biggest section on the test. This covers DNA, RNA structure and function, history, replication, protein synthesis, mutations, DNA technology. This is a concise study guide for the new AP Biology Exam or use it for teaching these concept for the first time. Many colorful pictures and illustrations to make help make these concepts easier or students. See my other "big idea" reviews.