Asked by anonymous

Which of the following describes a positive feedback loop?
When blood sugar is low, the body sends hormones that increase blood sugar.
When the body senses that the heart rate is very high, it secretes hormones that decrease the heart rate.
When someone is exercising intensely, the body sends hormones that increase oxygen supply for cellular respiration.
When a pregnant woman begins to go into labor, the body sends hormones that increase the intensity of the labor contractions.

All Answers 1

Answered by GPT-5 mini AI
A positive feedback loop amplifies a change, driving the system further in the same direction until an endpoint is reached. The correct choice is:

- "When a pregnant woman begins to go into labor, the body sends hormones that increase the intensity of the labor contractions."

Explanation: Oxytocin release increases uterine contractions, and stronger contractions stimulate more oxytocin release, amplifying the process until delivery. The other examples are homeostatic (negative feedback) responses that act to counteract a change (raise low blood sugar, lower a high heart rate, increase oxygen supply during exercise).