Not too sure how marks on a paper helps them figure out who I am but fine.
Well, its the same for any interview, good grades usually (not always!) translate into good workers.
For my final interview I was asked to talk through my whole CV history, starting from college. Part of that was explaining the grades, why I got the scores I did, how I dealt with the courses/workload, what I learned etc.
Providing evidence stops any overt fibbing for this section!