I find the science sequence at the high school dd12 is set to enter a bit frustrating for the same reason. You can't take AP bio until you've taken pre-AP bio; you can't take AP chem until you've taken pre-AP chem, etc. Basically, you have to take 2-3 periods of science every year in order to get into the higher level science classes.
Dd is signed up for pre-AP bio and earth systems science her freshman year but worries, in looking @ the books, that they'll be quantity over learning anything new. She had hoped to test out of the earth systems science course, which they used to allow, but they no longer allow that. It leaves very, very little time for other electives to take so many full year science classes in order to reach the higher level courses.
