To say that bio is "A LOT" of plant stuff is overstating it! If someone spent too much time focusing on that, they'd risk performing poorly on their exam. There IS plant stuff on the OAT, yes, but I doubt you'll be asked more than 4-5 questions max. (out of 40) that exclusively pertain to plants. Basically, you need to know the basics of plants (which, for some reason, a lot of OAT students apparently overlook) and if you don't, well, you're bound to get some questions wrong. People are good at remembering the questions that shock them, and for many people these are the plant questions from biology, but I assure you I clearly remember basically all the questions, by topic, from my exam, and yes there were a few plant-specific questions, but only a few. If you get six or more plant-specific questions, which is what I would consider "A LOT" then please let us know, because I'd be absolutely shocked (again, my test went nothing like that). My advice is, if you aren't comfortable with chloroplasts/photosynthesis (light and dark reactions) and basic plant structural stuff (like leaf structures/xylem and phloem/root stuff, specifically root nodules) then you should study it, but if you are comfortable with it, don't spend too much time reviewing it. I only say this because, there is SO much material that you can be asked on Biology, that I want you to be prepared for as much of it as possible.
I've talked to quite a number of past test-takers on their OAT experience, and here are the most common things that pop up:
1. Biology is VERY random* (See below)
2. Physics is easier (specifically, more straightforward) than most practice tests. Most physics review material comes from the MCAT, because there is NO physics section on the DAT (where all other OAT material is derived, and yes the DAT and OAT share the same question bank). The OAT physics is just a lot more straightforward, I feel, than the physics on the MCAT.
3. Quantitative Reasoning, for some odd reason, feels more difficult than the practice material for many people. I know that this has to do with psychological factors of fatigue, as well as timing issues, because the types of questions I was asked basically EXACTLY matched the kinds of things I kept seeing in the Kaplan review material. I've seen people complain about having to deal with 'crazy stuff' like trig. functions (including arc functions) and, I KNOW that this stuff is all over the Kaplan review material, so anyone who is complaining about stuff like that was clearly unprepared for their exam.
4. Reading Comprehension is very random, in that if the passages you happen to get just 'click' well for you, you are likely going to do well, and if not, then the opposite should be true. On my OAT, one passage (just one) didn't 'click' for me, and I struggled with it time-wise, and this messed up my timing on the other passages. As a result, I had to guess on a number of questions, and as a result I only got a 350 which, for me, was a big disappointment (it was by far my lowest score). I was consistently scoring 380 plus on my practice RC material. I realize that my score was still fine, so I'm ok with the outcome, as it helped get me into PCO (and getting into optometry school is really the only relevance of OAT scores).
*According to almost everyone I've spoken with, the biology section is quite random. For example, there were a couple topics that appeared on nearly every practice test I took (and hence that I extensively studied) that were entirely absent from my exam; at least I still knew the answer to every Biology question that was on my exam. Basically, because Biology covers such a wide range of topics, there is a tremendously diverse test bank of possible questions. I have NO clue how the computer decides which questions to pick! The only way to prepare for such a section is to just know as much as you can about all the topics that may be covered.
