31. When a child is sick and has a body temperature exceeding 37Å—C, the body 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.
When a child has a body temperature exceeding 37°C, the body's response to sweat in order to cool down is indicative of a negative feedback loop which aims to return the body to its normal temperature.
A) Positive feedback loop
A positive feedback loop amplifies a response or process, pushing a system away from its equilibrium state. In contrast, the scenario described involves the body working to reduce temperature, which is not consistent with the characteristics of positive feedback.
B) Negative feedback loop
This option is correct because a negative feedback loop functions to counteract changes and bring the system back to its set point. Sweating to reduce body temperature exemplifies this mechanism, illustrating how the body maintains homeostasis.
C) Both
This option is incorrect as the scenario described only aligns with the principles of a negative feedback loop. A positive feedback loop is not at play in the regulation of body temperature through sweating.
D) None of the above
This choice is also incorrect since the body's sweating response is indeed an example of a negative feedback loop. Therefore, stating that none of the options apply disregards the accurate physiological mechanism involved.
Conclusion
The correct answer is B, as the sweating mechanism in response to a raised body temperature exemplifies a negative feedback loop aimed at restoring homeostasis. All other options fail to represent the body's regulatory process accurately, as they either mischaracterize the feedback type or incorrectly claim that none are applicable.