But be warned, on all the Kaplan and AAMC online practice tests to cross out a wrong answer is the right mouse click. At the real test you use the left click on the text of the answer choice to cross it out.
Sounds ridiculous to mention I know, but they really don't give you enough time to read the whole tutorial, thus I figured it out 1/2 way through my Bio section! I was just assuming up to that point my right click was busted and crossing out wrong answers would have been a huge help for me.