Here's why:
* Photosynthesis: Plants, algae, and some bacteria use sunlight to convert carbon dioxide and water into glucose (sugar) and oxygen through a process called photosynthesis. This glucose is their primary source of energy, and they store it as starch.
* Food Chain: Animals eat plants (or other animals that eat plants), obtaining the energy stored in the glucose. This energy is then used for growth, movement, reproduction, and other life processes.
In summary: The sun is the ultimate source of energy for nearly all life on Earth. Even organisms that don't directly use sunlight, like deep-sea creatures, rely on food chains that ultimately trace back to organisms that photosynthesize.
