You got it! The sick-looking leaves on the right were grown in high-ozone air. Their color is much paler than the healthy leaves on the left because the ozone destroyed a lot of the green-colored chlorophyll (KLOR-o-fill). And plants need chlorophyll to make their food. Click here to learn how leaves make the plant's food.

What other damage do you see?

The healthy-looking leaves on the left were grown in the same air that had been filtered to remove the ozone.