At my institution, and with several professors in general, extra credit is awarded for perfect (or near perfect) attendance. This provides an incentive to attend class. It also provides an incentive for someone who is not attending class to ask a buddy to sign them in on the roster when it gets passed around. At my institution this is considered academic misconduct and you can be failed for the entire class for doing so. You also could, at least in theory, receive an IA on your transcript and thus destroy your chances at medical school.
I figured everyone would know this but pretty much every semester, in at least one of my classes, someone gets busted for doing it. The professors photocopy the roll sheets and then have their TA's look through them for discrepancies. Please, if someone asks you to sign them in, do yourself a favor and let them know you don't plan on throwing your med school hopes away just so that they can dodge class.
I figured everyone would know this but pretty much every semester, in at least one of my classes, someone gets busted for doing it. The professors photocopy the roll sheets and then have their TA's look through them for discrepancies. Please, if someone asks you to sign them in, do yourself a favor and let them know you don't plan on throwing your med school hopes away just so that they can dodge class.