Final answer:
The statement is true: negative feedback mechanisms maintain homeostasis by reversing changes, whereas positive feedback loops amplify changes and are activated only when there is a definite end point like in childbirth or blood clotting.
Step-by-step explanation:
The statement Negative feedback reverses changes in a system, while positive feedback amplifies changes in a system is true. Negative feedback mechanisms are essential for maintaining homeostasis, which means they help to keep the internal environment of an organism stable. When a deviation from a desired condition is detected, negative feedback responses act to counteract the change and bring the system back to its normal state.
In contrast, positive feedback mechanisms enhance or amplify changes; they lead to an increasing departure from the normal condition. Positive feedback loops are not as common as negative ones in biological systems because they push the organism further from homeostasis. However, they are necessary in certain situations, such as during childbirth or blood clotting, where a definitive endpoint is required.