Study Strategy
I used Mometrix Secret Study Guide Life Science 7-12, TexesPrep.com (bought 5 tests, only used 2), all of the Crash Course Biology and Ecology episodes (Youtube), College Bio Textbook, College Genetics Textbook, and Khan Academy. Utilizing different methods really helped me grasp the content. First I read through the Mometrix, which was very broad but it gives a decent overview. I purchased practice tests from TExES Prep. Some of their questions seemed poorly worded and a few of them didn't seem founded properly in what an educator should be expected to know. It was good to practice the motions of taking the test. I'd recommend finding actual test questions somewhere else. I must have gone through the Crash Course Ecology & Biology episodes a dozen times. If I got confused reading my book, I'd go back and watch the video and usually it helped. Every test answer that I had no idea what it was supposed to be - I looked those up, because if it's in an answer choice, it's there to make you doubt yourself. Khan Academy helped me stay savvy with older subjects I hadn't reviewed for a while. I don't have a degree in Biology or Science, but I did take a few entry-level Science courses throughout my college education.
Testing Strategy
I was really nervous about this test and actually postponed it a month after I took my first TExES Prep practice exam (which was MUCH harder than the real test). With two months of intensive free-time/weekend studying, I passed with a 277. The test was far easier than I ever possibly could have anticipated. Keep your study references general, but understand the concepts fully. You don't need to know every single protein involved in photosynthesis, just have a general idea of what's going on and you'll be fine. There are lots of diagrams, so brush up on your vocabulary.