Final answer:
In d. positive feedback mechanisms, an outside force must intervene to stop an escalating response that enhances the initial stimulus, such as with blood clotting or uterine contractions during labor.
Step-by-step explanation:
In the context of physiological processes, the scenario described refers to a condition where an outside force must intervene to halt a response that is escalating and enhancing the initial stimulus. This is characteristic of a positive feedback loop. Positive feedback mechanisms push the organism's physiology further away from its normal set points, amplifying the effects of the initial stimulus. Examples include blood clotting and uterine contractions during labor. In contrast, negative feedback mechanisms work in the opposite direction of the stimulus, seeking to negate or reduce its effect and maintain homeostasis. An example of negative feedback is the lowering of blood glucose levels after a meal.
The correct answer to the question is: d. Positive feedback
Summary of Key Points:
- Positive feedback mechanisms require intervention to stop an escalating response.
- Negative feedback mechanisms act to maintain homeostasis by resisting a deviation from a set point.
- Examples of positive feedback include blood clotting and labor contractions, whereas an example of negative feedback is the regulation of blood glucose.