Just to add my two cents... depending on your background, it can be in your interest to have them all done. I could have applied this past fall, and have completed the prereqs by this coming fall. But, I was low on the sciences and really wanted two A&P grades at the time of application review to show that I have science abilities. (I got an A last semester and am on track to get an A this semester.) If you have a situation like that... haven't taken a lot of science courses, or have a lower GPA, etc., you might want to wait even if these schools to which you're applying will accept your application.