[Campbell Biology P.945] Which of the following statements accurately describes the fundamen... | Practice Question

Which of the following statements accurately describes the fundamental difference between negative and positive feedback mechanisms in maintaining an organism's internal environment?

  • A: Negative feedback always leads to a stable set point, while positive feedback always leads to death.
  • B: Both negative and positive feedback mechanisms actively maintain an internal variable within a narrow, constant range.
  • C: Negative feedback mechanisms lead to a response that reduces the original stimulus, whereas positive feedback mechanisms amplify the stimulus, driving a process to completion.
  • D: An example of negative feedback is childbirth, and an example of positive feedback is blood glucose regulation.

Explanation

Negative feedback mechanisms are crucial for maintaining homeostasis; they detect a change and initiate a response that counteracts or reduces the original stimulus, bringing the variable back to its set point. Positive feedback mechanisms, in contrast, amplify an initial stimulus, pushing a process further in the same direction until a specific event is completed, such as uterine contractions during childbirth.