Process:  - Air is brought in through the mouth - Passes through the lungs - And into the bronchial tissue - The carbon dioxide is removed - The lungs bring the oxygen to the rest of the body.  Perturbation hypothesis: suppose there are no plants available happens, how will it affect a SMALLER amount of oxygen being delivered to the blood stream.  Does the supposed perturbation have an effect (direct or indirect) on the process?
Answer:
yes