Photosynthesis occurs in the chloroplasts within the leaves, where sunlight, carbon dioxide, and water are converted into glucose and oxygen.
The circulatory system, including the heart, blood, and blood vessels, ensures that oxygen and nutrients reach cells and that waste products are removed.
When water gains enough heat, its molecules move faster and escape as gas, a process called evaporation.
Gravity is the force of attraction between objects with mass. On Earth, it pulls objects toward the ground.
