A Simplified Model for Explaining Negative Feedback to Beginners in Life Sciences

Abstract

It may not be easy to present to beginners CO₂ and O₂ having the opposite effect on respiration, using the conventional diagram explaining negative feedback. In the new diagram we developed, the “cause”, its facilitating effect on the “result”, the facilitating and inhibiting noises on the “result”, the current magnitude of the “result”, the set-point, their comparison, and feedback effect on the “cause” are all clearly illustrated. For example, the engine RPM is the “cause”, increase in speed is the “result”, a downhill slope is the facilitating noise, and an uphill slope is the inhibiting noise. By having direction in the “result”, such as INCREASE in speed, INCREASE in O₂, and DECREASE in CO₂, the same diagram could be used to present CO₂ and O₂ having the opposite effect on respiration.