Get the ATI TEAS V Study Manual, & get as much out of it as you can.
Since all sections (in the study manual) deal with one Q. at a time, study time can be used in 5- & 10-min. increments if necessary.
If you are very limited in time until the exam, at least read the answers to the 2 sample tests in the manual--because the rationale of each Q. is explained; there is a lot of information in those answers.
RainbowDash has hit the high points for the Science section. It's useful to be able to set up a (simple) Punnett square, to say no more, even if a Q. may not require doing so.