Answer:
first, let's begin with plants they take in sunlight, water, and carbon then they turn that into glucose a by-product is oxygen so oxygen is released as the process of photosynthesis after you have that then we can get to animal process the animal breaths in give the lungs oxygen from the plants as the animal uses the oxygen it turns it into a by-product as well normally carbon we do this just to make ATP to function and you can feel how bad it is when your muscle cells don't have oxygen fully.
Step-by-step explanation:
sunlight, water, and carbon are absorbed by a plant to make glucose then the animal absorbs the oxygen to do basic functions and release carbon and the process begins anew.