1) Can you work well with others? Can you accept responsibility for your task, take on (volunteer) for additional responsibility if the team needs it, communicate effectively, support others, etc.
2) Definitely your role as a team member. However, the "team" question tends to already have a "trick" to it! As in they will likely already say "tell me about a difficult team you worked in" or "tell me about a team member you had a disagreement with".
3) Well, what do you think? Teamwork is as mentioned in #1 (all about you "giving"). Leadership is about you taking control / ownership, driving things forward, etc. etc. Now, remember, a good leader is also a team player and works well with others. So be careful to not go too far down the "I led the charge and did everything" route. But I think you now get the gist :)