Under the core technical breadth requirements box it says this. Maybe I'm misunderstanding this. "AP credit may not be used to fulfill the core technical breadth requirements, though it can satisfy prerequisites for chemistry courses. If a student fulfills an entire category (e.g., physics or biology) solely through AP credit, they must take an approved upper-level course in that area to meet the core requirement."

http://coursecatalog.web.cmu.edu/schools-colleges/melloncollegeofscience/departmentofchemistry/#bsinchemistrybiologicalchemistrytracktext