Here's why:
* Photosynthesis: Plants, algae, and some bacteria use sunlight to convert carbon dioxide and water into glucose (a type of sugar) and oxygen. This process, called photosynthesis, is the basis of life on Earth.
* Food Chain: Animals eat plants or other animals that have eaten plants. This means that the energy originally captured from the sun by plants is transferred through the food chain, ultimately providing energy for all living organisms.
While there are some organisms (like deep-sea vent creatures) that rely on chemical energy sources, the vast majority of life on Earth ultimately depends on the sun for energy.
