I wouldn't rely on anecdotal responses based on previous new mcat takers. For example, when I took the MCAT there were 3 biology passages that contained upper level genetics in some form or another. Two friends who took the test after me had ... guess what?... NO upper level genetics questions at all.
As previous posters have mentioned, no mcat is the same and I am assuming that this will be especially true for the new mcat exams as they are still in the novel stages of analyzing scores and such. My advice is to take as many practice exams as you can and assess the biochem content.