Question

photosynthesis is important to living organisms because it is the foundation of most food chains. the source of nitrogen gas in the air. how animals get carbon dioxide to breathe. the process that occurs in most ecosystems.

Explanation:

Photosynthesis is carried out by plants and some microorganisms. It produces organic compounds and oxygen using light energy, water and carbon - dioxide. These organic compounds are consumed by herbivores, which are then consumed by carnivores, forming the foundation of most food chains. Nitrogen gas in the air mainly comes from nitrogen - fixing processes and not photosynthesis. Animals breathe in oxygen, not carbon - dioxide. While photosynthesis occurs in many ecosystems, its key importance is in forming the base of food chains.

Answer:

the foundation of most food chains.