Final answer:
A negative feedback system in biology consists of three main parts: a sensor, a control center, and an effector. This system functions to maintain homeostasis by detecting changes, analyzing them against a set point, and then effecting a response to correct any imbalance.
Step-by-step explanation:
In a feedback system, specifically a negative feedback loop, there are several key components that maintain homeostasis. The first is the sensor or receptor, which detects any changes in the environment or within the body. This sensor then sends a signal to the control center, which is typically part of the nervous or endocrine system, such as the brain in mammals. The control center compares the incoming data against a set point, which is a normal range for the physiological value in question. If a discrepancy is found, the control center sends a signal to the effector to initiate a response to correct the imbalance. Effectors in these systems can be organs, glands, or muscles that act to return the physiological value back to its set point, thereby maintaining homeostasis.
An example of a negative feedback mechanism is body temperature regulation. If the body's temperature deviates from its normal range, the control center in the brain registers this change through signals from temperature receptors and then activates effectors like sweat glands or muscles to either cool down or heat up the body, thus reversing the change and stabilizing the temperature.