Give a lemon to each student and ask them to "get to know" their lemons. Have them look for any identifying marks, shape, brightness of the lemon, etc. Then, take the lemons, put them in a basket and have the students find their lemon. Students should not have trouble with this. The next day, peel the lemons and have the students attempt to find their lemons again in the basket. This will teach them that although we look different on the outside, we are the same on the inside.