Which of the following is true of positive feedback mechanisms?

• A. They amplify the initial stimulus.
• B. They are more common than negative feedback mechanisms in the body.
• C. They help maintain homeostasis by counteracting changes.
• D. They typically involve a decrease in the original stimulus.

Answer: (A)

Verified step by step guidance

1. Understand the concept of feedback mechanisms: Feedback mechanisms are processes that help regulate physiological functions in the body. They can be either positive or negative.
2. Define positive feedback: Positive feedback mechanisms amplify or increase the initial stimulus, leading to an enhanced response. This is in contrast to negative feedback, which works to reduce or counteract the stimulus.
3. Identify examples of positive feedback: Common examples include the process of childbirth, where the release of oxytocin increases contractions, and blood clotting, where the presence of a clotting factor leads to the production of more clotting factors.
4. Compare positive and negative feedback: Negative feedback mechanisms are more common in the body and are crucial for maintaining homeostasis by counteracting changes. Positive feedback is less common and typically does not maintain homeostasis.
5. Evaluate the statements: The statement 'They amplify the initial stimulus' is true for positive feedback mechanisms, while the other statements are characteristics of negative feedback mechanisms or incorrect descriptions of positive feedback.