Video narration
Where does the potted plant by your window get its food? You give it water, and it stands in soil, so it's easy to think the soil is its meal. But soil isn't the plant's food. It can take water and minerals from the soil, but those aren't its meal. The green leaves do the food-making. In its leaves, sunlight helps it use water and carbon dioxide from the air to make the sugar it needs. That's photosynthesis: the plant's way of using light to make its own food. As it makes sugar, oxygen is released into the air too. The oxygen is a result of the process-not the food the plant is making. That potted plant makes its own food: sugar, using sunlight, water, and carbon dioxide from the air-and it releases oxygen.