This is a low-cost way for students to practice using dissection tools without wasting expensive dissection specimens. It is also a way for students who are hesitant to participate in dissection to become more comfortable because it doesn't use actual animals.
This uses grapes. I usually place them in a jar filled with water and food coloring and make a big production about carefully removing them from their container. The kids have a lot of fun and because grapes are cheap, everyone can dissect their own specimen.