What do race and ethnicity mean to you?
Since this is your question, I suggest you answer it. Your teacher wants to know what YOU think -- not what some anonymous person online thinks about it.
It might help to think of your friends and what would happen to your feelings toward them, if they were of a different race, religion or ethnic group.
Here are some sources on prejudice that might help you explore your own thoughts and feelings.
http://virgil.azwestern.edu/~dag/lol/PrejudiceUsThem.html
http://virgil.azwestern.edu/~dag/lol/PrejudiceCauseSolution.html
I hope this helps. Thanks for asking.
I have already answered this. I was just looking to see what other people thought