Question

Which of the following describes a negative feedback loop?
When the heart rate is too high, the body sends hormones that continually increase the heart rate higher.
When a pregnant woman is in labor, the body sends hormones that increase the intensity of contractions, which then increases the secretion of the same hormones.
When blood sugar is too low, the body sends hormones that raise blood sugar until it reaches a typical level and hormone secretion slows.
When a person is jogging, the body sends hormones that continually decrease the rate of oxygen supply to the legs.

Answer 1

"When blood sugar is too low, the body sends hormones that raise blood sugar until it reaches a typical level and hormone secretion slows."

This is negative feedback because the response counteracts the deviation and reduces the original stimulus (hormone release). The others describe positive feedback or are incorrect: the labor example and the heart-rate example amplify the change, not reduce it; the jogging example would not be a compensatory response.