Answer:
Use substances in the air as a major source of carbon.
Explanation:
Photosynthesis is the process wherein green plants fix the atmospheric carbon dioxide (CO2) into glucose in the presence of sunlight. The process uses CO2 as a source of carbon, sunlight as a source of energy and water molecule as a source of electrons to drive ATP and NADPH synthesis. Grasses are also photosynthetic organisms that can make organic nutrients by the process of photosynthesis. Stomata present in the leaves of grasses allow the atmospheric CO2 to enter the mesophyll cells followed by sunlight driven fixing of CO2 into glucose.