Destroyer bio is not comparable to DAT bio questions because the way it is asked in destroyer is more to put as much information in your brain as possible. For example they have a lot of questions like "which of the following are true" and then the answer is "all of them". Just treat bio on it as a source of info, not practice. Chem and ochem on the other hand, treat it like they are the answers to the real test aka, memorize. It's much harder than the actual DAT but if you know how to do destroyer chem/ochem well (i mean not look up the answer and say "oh yeah") then the actual DAT will be a walk in the park.