1. Biggest surface area? Biggest volume? Biggest surface area to volume ratio?

3. TEM micrograph of mitochondria in human lung tissue cell

5. Some of the answers people gave: “It increases the surface area so it can have more room.” “There is more surface area for reactions.” “It has more surface area to function with more folds.”

7. Cabbage leaf

8. Whale’s body

9. Small intestine wall

10. Penis

11. Fish gills

12. DNA molecule