Homeostasis and Feedback Systems Practice Quiz (4 questions)

1. What does homeostasis describe?

A. Adjusting the external environment to match the body’s internal conditions

B. Keeping the body’s internal conditions fixed regardless of external changes

C. Maintaining a relatively stable internal environment despite changes in the body or surroundings

D. Allowing internal conditions to change in response to surrounding conditions

Answer: (C)

Explanation

Homeostasis maintains a relatively stable internal environment even as conditions inside or outside the body change. Keeping conditions entirely fixed is a misconception because stability does not mean an absence of variation.

2. A person’s body temperature fluctuates slightly during the day but remains within a normal range. Which principle does this illustrate?

A. Temperature regulation varies the set point to match changes in the surroundings

B. Temperature is regulated around a set point that changes substantially throughout the day

C. Temperature is regulated around a set point of about 37°C, within a normal range

D. Temperature is held at exactly 37°C, with fluctuations indicating failed regulation

Answer: (C)

Explanation

The body-temperature set point is about 37°C, and regulation keeps temperature within a normal range rather than at an exact unchanging value. The idea that any fluctuation indicates failed regulation confuses a relatively stable range with a perfectly fixed temperature.

3. A rise in a regulated condition triggers a response that reduces that rise and moves the condition toward its set point. What type of feedback is occurring?

A. Passive regulation, because the condition changes without an opposing response

B. Positive feedback, because the response reinforces the initial stimulus

C. Feedforward control, because the response precedes the initial stimulus

D. Negative feedback, because the response opposes the initial stimulus

Answer: (D)

Explanation

Negative feedback opposes the initial stimulus and helps return the regulated condition toward its set point. Positive feedback is the plausible contrast, but it reinforces rather than counteracts the initial change.

4. In a physiological feedback system, what follows a stimulus and can affect the regulated condition?

A. A stable internal environment

B. A response

C. A surrounding condition

D. A set point

Answer: (B)

Explanation

A feedback system involves a stimulus followed by a response that affects the regulated condition. A set point is a reference condition, not the response that follows the stimulus.