Question

how can say that photosynthesis maintain balance between oxygen and carbon dioxide in the atmospher ?

Answer 1

because in photosynthesis CO2 is taken and O2 is liberated If it does not happens then CO2 in atmosphere will increase

Answer 2

Photosynthesis is a process in which plants made their food. In this process sun light, carbon dioxide and water is used. And oxygen is release as biproduct. So we can say that photosynthesis balance oxygen and carbon dioxide. And this phenomena credit goes to plants because if Here is no plants on the earth the balance of gases are not mantain after this no any living organism can survive on earth.