... After speaking with many schools the way i understand it, there are two main tracts you could take.  I know that majoring in biology is one way but  what i was looking into was more exercise based.  From what i collected, it seems that a major in Exercise science with an emphasis in pre-PT will prepare you for graduate school.  but this all just depends on where you go for undergrad and what they may emphasize there, so speaking with someone at your school to find out which of these two are suggested would probably be the best idea.  hope my rambling helped... Good Luck!