[ Music ]
The view of these trees in mid-October is much different than the view of these trees in the month of June. What accounts for this difference? The answer lies in the color of the leaves on the trees. Here in New England, leaves turn brilliant colors in autumn, changing from their usual green color in spring and summer. What are leaves and why are they important? Leaves come in many shapes and sizes. The leaves of these rain forest plants are quite large, whereas the leaves of duck wheat are tiny. Some leaves have a general round shape, and other leaves are thin and pointed. Some plants, such as pine trees, have needles instead of leaves. And many cactuses have sharp spines. We eat leaves, including lettuce leaves. You decide. Why are leaves so important to plants?
[ Music ]
Leaves are extremely important because they are the main food-making factories of plants. Through a process called photosynthesis, plants are able to make food from the sun's energy along with water and a gas called carbon dioxide. In turn, a gas called oxygen is produced as well as sugars, which the plants used for food. Leaves capture the sun's energy. The more leaves a plant has, the more energy it can potentially capture. While not all plants have green leaves, the vast majority of them are green. Why? The process of photosynthesis occurs within structures called chloroplasts, which are located inside plant cells. Chloroplasts contain a green substance called chlorophyll, which plays a vital role in trapping the sun's energy. Chlorophyll causes the dominant green color seen during the plant's growing season. But when the growing season winds down, green chlorophyll becomes less visible and other colors in plant cells emerge.