<span>1. Breathing moves air in and out of the lungs.
2. Oxygen diffuses from alveoli in the lungs into capillaries.
3. Oxygen enters red blood cells, where it binds to the protein hemoglobin.
4. Oxygen diffuses from the blood to the body's tissues, and carbon dioxide diffuses from the tissues to the blood.
5. Carbon dioxide leaves the body when exhale.</span>
A heterogeneous mixture composes of non- uniform components, so the concrete would be the answer, because you can tell the components from one another.
Due to the fact that all the organisms are connected in a chain, the energy flow would be affected and that would result in many organisms being deprived of energy they need and that creates a chain effect.
