I did a search for all "Question bank" related questions and could not find my this question, so it may be that I'm missing something fundamental. 

I am in the process of cleaning up question banks in my courses. Due to the need to import from other courses in order to copy quizzes and other assignments, I have a jumble of duplicate questions in my banks. 

What I need some clarification on is, if I delete all duplicate instances of a question, meaning I'm left with just one copy of that question, will deleting those duplicate instances affect its showing up on a quiz? If so, is there a way to determine which instance of the question is in use? 

Thank you for the help.