That's the secret of Penn, I think -- they are completely ambiguous with regard to pre-reqs. I think this basically means that they're the same as for other schools. At one point when I was in grad school there I was told I might be able to get into the med school without a second semester of physics. Not sure if this was because I was already a student or what. They just have this lofty desire to require proficiency in all of the required pre-reqs without actually requiring a specific set of courses.
(I think.)
(edit: I used variations on the word "require" a record number of times in that last sentence)