How should I study and organize to get a solid 750+ on the Bio SAT II?

Hi, this is my freshman year and I’m been practicing and reviewing almost 24/7. I have books from Kaplan, PR and Barron’s but I can’t really make it past a 700. I have taken many practice tests. My scores are 560, 610, 630, 660, and 690. What should I do?

Are your missed questions concentrated in one area?

Sorta but not really. I suck at plants, nervous systems and things that require you to memorizing it.