Final answer:
Positive feedback is a process where a biological system amplifies the initial change, moving further from equilibrium, which is exemplified in processes like blood clotting and childbirth.
Step-by-step explanation:
Positive feedback in biological systems is a process in which a change or stimulus creates a response that amplifies the direction of the initial change. It is a mechanism that intensifies a response until a certain endpoint is achieved. This type of feedback loop can result in an accelerated and sometimes unstable process as it moves the system further away from its initial state.
Two primary examples of positive feedback loops in the human body are blood clotting and childbirth. During blood clotting, a cascade of reactions occurs where each clotting factor activates the next one, leading up to the formation of a fibrin clot. In childbirth, the hormone oxytocin is released to stimulate uterine contractions, which then leads to more oxytocin being produced until delivery is achieved. Both processes are normal but are only activated under specific conditions that require these feedback loops.
Other examples of positive feedback outside of biological systems can include the growth of bacteria populations where the presence of more bacteria speeds up their rate of reproduction, leading to exponential growth. It's vital to understand that unlike negative feedback, which strives to maintain equilibrium, positive feedback tends to move a system away from its normal range of functioning.