Which of the following is an example of homeostasis? A. During a time of high stress, Justin's heart races, his muscles tense, a
nd he feels sweat dripping down his forehead. B. Sick with the flu, Alison's body temperature rises to fever levels. C. Boris doesn't drink very much water one day. To compensate, his kidneys remove less fluid from his blood, and produce less urine than normal. D. As Grace races up the ten flights of stairs to her apartment, the muscle cells in her legs produce excess lactic acid, causing a burning sensation in her legs.
Homeostasis refers to the tendency for the human body to attempt to maintain a certain state even during changes in environment, activity, intake, etc. Options A, B, and D all refer to instances where the body departs from its usual state. While the scenario in Option C does describe a change in environment, it also describes the reaction of the body that brings its internal systems back to a certain state of fluid level.
Prions, however, are not living organisms. Prions are infectious proteins. For unknown reasons, these proteins refold abnormally and cause a domino effect in surrounding proteins which in turn mutate into stable structures
