Question

Mrs. Thorne asks her class to give an example of a negative feedback loop. Which student has the BEST example?

Responses:

Eddy says, “Blood clotting at the site of a cut.”

Bianca says, “The contractions a mother has during childbirth.”

Jorge says, “The pancreas secreting insulin to regulate blood sugar.”

Paz says, “Itching happening because of an allergic reaction.”

Answer 1

Jorge. Secreting insulin in response to high blood glucose is a classic negative feedback loop: the response (insulin) reduces the original stimulus (high blood sugar).

(Eddy and Bianca describe positive feedback—clotting and childbirth amplify a process—and Paz’s example is a symptom of immune activation, not a homeostatic negative feedback.)