Final answer:
Feedback that causes a system to increase its output is called positive feedback, which includes biological examples like blood clotting and uterine contractions during childbirth.
Step-by-step explanation:
The term for feedback that causes a system to increase its output is called positive feedback. This kind of feedback loop maintains the direction of the stimulus, sometimes even accelerating its effect. An example of this in biology is the process of blood clotting. As one clotting factor is activated in the body, it sets off a chain reaction that activates the next factor, leading up to the formation of a fibrin clot—a type of positive feedback.
Likewise, during childbirth, the hormone oxytocin stimulates the contraction of the uterus. The ensuing contractions, which cause pain, lead to the production of more oxytocin, intensifying the contractions until childbirth is achieved, fitting the definition of a positive feedback loop.