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AP Biology Practice Quiz: Feedback

Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026

Test your understanding with short quizzes. This quiz has 7 questions to check your progress.

Question 1 of 7

According to the provided information, what is the primary role of a negative feedback mechanism in an organism?

All Questions (7)

According to the provided information, what is the primary role of a negative feedback mechanism in an organism?

A) To amplify the initial stimulus, causing a rapid change.

B) To reduce the initial stimulus, helping to maintain a target set point.

C) To move the internal environment further from its initial state.

D) To create a new set point for the internal environment.

Correct Answer: B

The text explicitly states, 'Negative feedback reduces the initial stimulus to maintain a target set point.' Options A and C describe the function of positive feedback.

An organism's internal system experiences a change. A feedback mechanism is initiated that amplifies the response, causing the system to move even further from its initial set point. This process is best described as:

A) Homeostasis

B) Negative feedback

C) Positive feedback

D) A target set point

Correct Answer: C

The text defines positive feedback as a mechanism that 'amplifies responses, moving the system further from the initial set point,' which directly matches the scenario described in the question.

Which of the following statements correctly distinguishes between negative and positive feedback mechanisms based on the provided content?

A) Negative feedback amplifies a stimulus, while positive feedback reduces it.

B) Both mechanisms work to move a system further from its set point.

C) Negative feedback maintains an internal environment around a set point, while positive feedback moves it away from a set point.

D) Only positive feedback is used by organisms to maintain their internal environments.

Correct Answer: C

The provided text states that negative feedback works 'to maintain a target set point,' whereas positive feedback 'amplifies responses, moving the system further from the initial set point.' This makes option C the most accurate comparison.

How do the feedback mechanisms described contribute to maintaining homeostasis?

A) By exclusively using positive feedback to amplify all changes.

B) By regulating and maintaining internal environments through responses to stimuli.

C) By constantly changing the target set points of the system.

D) By preventing any stimulus from affecting the organism's internal state.

Correct Answer: B

The text begins by stating, 'Organisms use feedback mechanisms to maintain internal environments,' which is the essence of homeostasis. The mechanisms described (positive and negative feedback) are the means by which this regulation and maintenance occurs.

A particular feedback mechanism in an organism acts to counteract and reduce the effect of an initial stimulus. This is an example of:

A) Positive feedback

B) An amplified response

C) Negative feedback

D) A shift away from a set point

Correct Answer: C

The content explicitly states that 'Negative feedback reduces the initial stimulus.' The question describes this exact process of counteracting a change.

Which feedback mechanism is primarily characterized by its function to maintain a system at or near a specific target set point?

A) Positive feedback, as it amplifies the response to reach the set point faster.

B) Negative feedback, as it reduces stimuli that cause deviation from the set point.

C) Both positive and negative feedback, as they work together to establish the set point.

D) Neither, as set points are static and not maintained by feedback.

Correct Answer: B

The provided text directly links negative feedback with the goal 'to maintain a target set point.' Positive feedback is described as moving the system away from the set point.

Based on the provided description, what is the expected long-term outcome of a system dominated by a positive feedback loop?

A) A return to a stable, initial set point.

B) A reduction in the intensity of the initial stimulus.

C) The stabilization of an organism's internal environment.

D) A progressive and amplified deviation from the initial state.

Correct Answer: D

The text states that positive feedback 'amplifies responses, moving the system further from the initial set point.' This continuous movement away from the starting point results in a progressive and amplified deviation. Options A, B, and C are all characteristic outcomes of negative feedback.