The purpose of the assignments are to give you practice in group roles and leadership. In the work place you would not think of continually doing someone else's job for them and letting them collect their paycheck for doing nothing. You would also be unlikely to continually give credit for your work to others. It is listed here so you will have a fair way of handling a member who is not performing adequately. You must discuss your concerns about the member's performance and your criteria for acceptable performance with the member in question.
Offer advise on improving performance.
If there is no improvement in the member's performance, schedule a meeting with the entire group and me to discuss the continuing problem. If at that meeting, or subsequently, the group votes to fire the member, the dismissed member must take the initiative to make arrangements with me to individually complete the credits assigned to the group activity.