This is where I feel people over-do the Bio section. Because it is so random, people tend to (myself included) dive to deep into detail on topics like this.
Understanding the difference in the two in great detail would be substantial; however, for the DAT you will most likely only need to know: Hemoglobin= O2 transport in blood whereas Myoglobin= O2 transport/storage in muscles. That is just an example, but most questions will require knowledge on the general concepts more than the deep detail.
Keep it basic. Remember, not everyone applying is a Biology major, so know the general ideas behind terms/concepts. It's often not the questions pertaining to ideas like this that people miss because they studied it so well. The basic things that people neglect, for example Taxonomy, tend to come back and bite you in the a** on a question. IMO- Bio is too random come test day to really ever feel you fully learned and retained what you needed, so understand the general concepts first and master your chemistry sections, and def. PAT and then revert back to BIO for more detalied concepts.
I was a Bio major and thought I had a grip on Bio no problem, but ended with an 18 each time. Thankfully, I did well on my chem to jack up my TS and did well on RC to help my AA because I knew QR would be my worst section. Best of luck.
