This is one of my favorite activities! The students really have a lot of fun with this lesson. After a brief talk about how the DNA in each of us is different, I relate that to how each food item has a different bar code as well. I use bar codes (DNA samples) and place them around my room on various objects. The students have to match the DNA sample (bar code) with the bar codes on their paper to see which perpetrator was at that particular crime scene. You can change the names on the bar code sheet to match the items in your classroom. Have fun with this one!! This activity supports Grade Seven California State Science Standard 2E - Students know DNA (deoxyribonucleic acid) is the genetic material of living organisms and is located in the chromosomes of each cell.