AP BIOLOGY

Detailed explanation-1: -If we look at a system in homeostasis, a positive feedback loop moves a system further away from the target of equilibrium. It does this by amplifying the effects of a product or event and occurs when something needs to happen quickly.

Detailed explanation-2: -Positive feedback enhances or amplifies an effect by it having an influence on the process which gave rise to it. For example, when part of an electronic output signal returns to the input, and is in phase with it, the system gain is increased.

Detailed explanation-3: -Examples of processes that utilise positive feedback loops include: Childbirth – stretching of uterine walls cause contractions that further stretch the walls (this continues until birthing occurs) Lactation – the child feeding stimulates milk production which causes further feeding (continues until baby stops feeding)

Detailed explanation-4: -Homeostasis typically involves negative feedback loops that counteract changes of various properties from their target values, known as set points. In contrast to negative feedback loops, positive feedback loops amplify their initiating stimuli, in other words, they move the system away from its starting state.