Very interesting topic - thanks, as usual, for bringing it up!
It's on my mind these days too, mostly because ds13 just set his probable course of study in high school in consultation with the heads of the math and science departments at the high school he will attend this fall.
Years ago, I followed what I have long assumed was the common path in high school: Biology, Chemistry and Physics, in that order. But the math and science heads advised ds to take AP Physics B in 9th, AP Physics C in 10th, AP Chem in 11th, and AP Bio in 12th. (Their advice was based partly on the fact that he took Bio in 7th and Chem in 8th via CTD.)
I thought maybe his path was atypical because his math sequence is unusual -- he's aiming to take a joint AP Calc BC - AP Physics C course in 10th. But the science head actually said he thinks this science sequence makes a lot of sense on its own terms, because he thinks of biology as the most complex or interdisciplinary of sciences (sorry, I can't remember his exact choice of words).
So it was very interesting to read that EPGY and Avid Academy recommend a similar course of study.
