T


he trees in the forest are full


of sound. Birds squawk and chirp. Monkeys call. Snakes hiss. Suddenly, there’s a buzzing sound.


It grows louder. It’s a man! He is flying over the trees. A buzzing glider is strapped to his back. Meet Mark Olson. He’s a botanist


who studies trees. He’s flying over the treetops to look at leaves. He studies tree leaves to see how they use sunlight.


Leaves at Work Olson knows that leaves use the sun’s energy to make food. T is is called photosynthesis. Plants mix water with carbon


dioxide gas. T is makes the plant’s food. It also makes the oxygen that we breathe. Olson gets ready to land. T e


glider carries him to the ground. He lands gently near the trees he’s been studying. T ey’re called moringa trees. People use this tree’s leaves and


roots for food and medicine. Some people call them miracle trees. To Olson, the miracle is what happens inside each leaf.


20 oxygen is released


Using Sunlight At night, most tree leaves rest. At sunrise, the leaves get to work. T ey open their tiny pores, or holes. Water vapor enters the pores. Carbon dioxide enters, too. Chlorophyll inside the leaves soaks up the sunlight. Deep in the soil, the roots take


in water. T e water goes up the trunk. It goes into each branch and leaf. Photosynthesis begins. A tree needs thousands of leaves to keep it alive. From morning to night, they make food for the tree.


PHOTOSYNTHESIS


A leaf turns sun, water, and carbon dioxide into food and oxygen.


light energy enters leaf


water enters leaf


sugar leaves leaf


carbon dioxide enters leaf


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