23. A child is sick. They have a body temperature that exceeds 37Å—C. The body senses this and begins to sweat in order to lower the temperature. What is this an example of?
Answer: B
This is an example of a Negative feedback loop.
In this scenario, the child's body temperature exceeds the normal level, prompting the body to initiate a response—sweating—to bring the temperature back down to the normal range. This regulation mechanism exemplifies a negative feedback loop where the body's response counteracts the initial stimulus.
A) Positive feedback loop
A positive feedback loop amplifies a change or process, leading to an increase in the output or effect. In this case, sweating does not enhance the fever; rather, it serves to reduce the body temperature, making this option incorrect for the described scenario.
B) Negative feedback loop
This choice is correct as it accurately describes the body's mechanism of sweating to lower an elevated temperature. Negative feedback loops work to maintain homeostasis by reversing deviations from a set point, which is exactly what occurs in this situation.
C) Both
This option is incorrect because the scenario specifically illustrates only a negative feedback loop. While both feedback mechanisms can occur in biological systems, this particular instance does not involve any amplifying process characteristic of positive feedback.
D) None of the above
This choice is incorrect as it suggests that the situation does not represent any feedback mechanism. However, the child's response through sweating clearly exemplifies a negative feedback loop aimed at restoring normal body temperature.
Conclusion
The correct answer is B because the child's sweating is a clear example of a negative feedback loop, which aims to counteract the increase in body temperature. All other options either mischaracterize the mechanism involved or fail to acknowledge the regulatory process that is key to maintaining homeostasis.