Final answer:
Negative feedback in biology refers to the process where a change in a physiological condition triggers a response that reverses that change. It's vital for maintaining homeostasis, as seen in the regulation of blood glucose and calcium levels, as well as body temperature regulation.
Step-by-step explanation:
An example of negative feedback is the way the endocrine system regulates hormones to maintain homeostasis. When blood glucose levels are high, the pancreas secretes insulin, which lowers the glucose level. Conversely, if glucose levels are too low, the pancreas releases glucagon to increase blood glucose. Similarly, for blood calcium regulation, if calcium levels fall, the parathyroid gland releases parathyroid hormone (PTH) to raise the calcium level through increased absorption and possibly breakdown of bone. These responses correct the initial stimulus, hence the term negative feedback. It's a crucial regulatory method that sustains a stable internal environment or homeostasis.
Another example is body temperature regulation, where a high temperature triggers mechanisms such as sweating to cool down, while a low temperature may initiate shivering to generate heat. Once the temperature stabilizes, these responses diminish, illustrating the self-regulating nature of negative feedback loops.