Tonight we've been discussing the oxygen and water cycles and how food chains support life on earth. We've learned that this little leaf can work a miracle.

Who can tell me what the miracle is? This leaf is a food factory - it can make food by using the sunlight to turn nutrients

from the soil and carbon dioxide into food. And at the same time, it produces the oxygen that we and wildlife must have to live.

Life could not exist without the miracle represented by this leaf and all the other plants that can perform the miracle.

What's the point in this lesson in biology? The point is that because we can't survive without plants, it is in our own interest to make sure that this food factory survives. And that's why we must

fight pollution and why we must practice conservation like planting trees and shrubs. The whole idea is to encourage these little food factories to produce food and oxygen for wildlife and ourselves.