This was an incredibly moving story to me, and discussing it in a literature circle is something I would love to do. Here are some discussion questions that come to mind immediately:
1. How can one find purpose and meaning in life if one is created only for the good of another?
2. Is this book in any way an argument for or against cloning? Why?
3. Does it make a difference to our lives if we know the reason we will die?
4. Is a purposeful death better than a death without purpose?
5. Would this story have "worked" in the same way if the clones had not been isolated? How would the story have been different?
6. To what degree is this story a commentary on the haves and the have-nots? What supports this?
Good luck with your discussion!