biology test for someone who hasn't taken ap bio

I’m trying to figure which SAT subject tests I should take. Though SAT II biology is apparently the easiest science test to take, how difficult do you think it would be for someone who hasn’t taken AP bio? Of course I plan to use a review book to study for it, but still… I took regular biology my freshman year and it was really easy.
Has anyone else taken the SAT biology test without taking AP bio?

AP Bio is not needed for the AP subject test, although some students do take it after taking AP Bio.

I took the Biology E test after taking Honors Biology in 9th grade. I got a 620 with not much studying. After taking AP Bio as a sophomore I took it again, but the molecular one. For this one I got a 740 (again, without much studying). I think you’ll probably do well with some studying.