Go through the destroyer for biology and circle the questions that were causing you any trouble.
You would want review these problems that you circled everyday. This should probably take less than 1-2 hours a day if you are scoring at least a 70% on the biology section. After the 3rd day, it will take probably take less than 30 minutes.
By this time, you will began to notice key words for each question and start associating with other biological terms. For example, flat worms = acoelmate. You may not know this information on the first day, but after a few days, you will realize that you can associate one sentence or key fact per question.
Any questions that you circled, you would want to go through your notes and focus on the surface of the material. If you are learning about epitope, then you would want to start looking at immune system again to refresh everything. This shouldn't take longer than 15-25 min.
Lastly, if you have not done so yet, you should take bootcamp practice exam every single day until your exam. Really similar to the actual DAT.