Answer:
Oxygen is returned to the atmosphere through photosynthesis.
Photosynthesis
- Photosynthesis is the process used by green plants and a few organisms that use sunlight, carbon dioxide and water to prepare their food.
- Plants, algae, and certain bacteria use the photosynthesis process to turn light energy into chemical energy.
- Photosynthesis produces glucose, which provides organisms with two essential resources: energy and fixed carbon.
