On my version, I didnt get any diagram where I had to label things like you mentioned, but for example, I think you should know organelles of a cell and how they look like (i.e. mitochondria, ER, nucleus) I also got a random picture of bar lines, I think that was from cell biology class, where like if a protein is glycosolated, it should be heavier, so the bar line should be lower(?) Im not sure on that, you might wanna check, I didnt do too hot in that class, and it came back to hunt me again on the OAT. But dont worry too much about labeling pictures, for me there was a MAX of 2-3 ques on labeling 🙂