Can a course taken at another institution be used to fulfill a General Education requirement?

Yes.  As with AP credits, when academic credit is assigned for a course taken at another institution, that course is "linked" with a UK course.  Any UK Core requirement fulfilled by that UK course is also fulfilled by the transferred course.  As always, please see your academic advisor regarding specific questions. The Office of the Registrar maintains a database that allows you to check on your potential transfer credit(s).