Why is photosynthesis important to all life on earth?
It supplies life on earth with energy, harnessed from the sun.
The sun releases a lot of energy through constant nuclear reactions (the fusion of hydrogen). Plants have the ability to use the light energy it releases to produce glucose which they can then store and use. This stored glucose (stored as starch due to it being insoluble) is then consumed by the next organism in the food chain. This could be a herbivore (like a rabbit eating some grass), a microorganisms (like yeast fermenting glucose in the beer industry) or an omnivore (a human eating some mashed potato).
The energy from the sun is passed down the food chain (sun - plant - herbivore - carnivore/omnivore) supplying the whole food chain and earth with energy.
Hope this helps:)
First of all, Photosynthesis is only important for green plants its not important for each and everyone in a direct way.
Photosynthesis is important mostly for Green plants as they make food from that process.
Oxygenic photosynthesis is written as follows:
6CO2 + 12H2O + Light Energy → C6H12O6 + 6O2 + 6H2O
In indirect way plants use photosynthesis to make their food and grow. Then herbivores and omnivores eat those plants and gain energy which is stored in the plants and after that carnivores and omnivores eat them. And this way the life cycle goes on.
So that is why Photosynthesis is necessary for all living things and or life.