You don't. Seriously, you study the best you can and then hope to get a good test. On practice tests I was ranging from a 21 to a 15 in bio. I ended up with a 24. Study broadly.
In addition to OP question. Im just wondering why there isnt a wider support for buying/making bio flash cards...? Being that its for the most part is memorization (more so than any other section IMO) I would assume theyd be useful. Am I wrong?