Answer: 1. It is the number one source of oxygen in the atmosphere.
2. It contributes to the carbon cycle between the earth, the oceans, plants, and animals.
3. It contributes to the symbiotic relationship between plants, humans, and animals.
4. It directly or indirectly affects most life on Earth.
5. It serves as the primary energy process for most trees and plants.
Explanation: Photosynthesis is important to live organisms because it is the number one source of oxygen in the atmosphere. Without photosynthesis, the carbon cycle could not occur, oxygen-requiring life would not survive and plants would die. Green plants and trees use photosynthesis to make food from sunlight, carbon dioxide, and water in the atmosphere: It is their primary source of energy. The importance of photosynthesis in our life is the oxygen it produces. Without photosynthesis, there would be little to no oxygen on the planet.