The document discusses the main plant parts and their functions, including roots that take in water and nutrients from the soil, a stem that transports water and food throughout the plant and holds it upright, leaves that perform photosynthesis using carbon dioxide, sunlight and water to produce oxygen and energy for the plant, and flowers that attract pollinators to help the plant reproduce and produce seeds. It emphasizes that plants are important to habitats by providing beauty, food, shelter and more.