Question

how can you say photosynthesis maintains balance between Oxygen and Carbon dioxide in the atmosphere?

Answer 1

Photosynthesis is literally the most important thing to the ecosystem, and in short is the source of all chemical energy (the kind the organisms use) in the ecosystem. Photosynthesis allows plants to make energy and food for themselves by converting light energy into chemical energy, and some of this chemical energy is stored in the form of various sugars, along with the other nutrients that the plant picks up from the soil. This is why plants that perform photosynthesis are known as Producers, because they produce all of the original chemical energy in the ecosystem. When primary consumers come and eat the producers, they get about 10% or less of the energy stored in that part of the plant (say, a tomato). Then when the secondary consumer eats the primary consumer, the secondary consumer gets .1% of the original tomato's energy, and the tertiary consumer that eats the secondary consumer gets only .01% of the original tomato's energy. This is why most ecosystems have the dominant organism as a tertiary consumer, and it rarely goes to Quaternary consumer. But in a more condensed form: Photosynthesis is the process by which all energy in the ecosystem is made.