you really don't need to take an entire class on genetics to do the genetics problems or physiology to answer the problems on physiology. Basic freshman 100 level biology is all you need to get 20s on the DAT. The only advanced bio courses I took was neuro and biochem and I still got a 23 on the bio section. I mean, if taking those courses fulfills your degree requirements, by all means take it. Especially a class like anatomy, which will actually help you in dental school since you will already be familiar with the subject when you take it again. Don't take the class just to do well on the DAT though, because i don't see the point of taking an entire course to answer 2 or 3 questions on an exam. You'll find every single answer to the bio section of DAT in your general biology textbook. Also, get Schaum's Bio outline. I heard it's very good in terms of content.