negative feedback questions
Choose the correct answer for each question. The following links will take you to diagrams of negative feedback paths. diagram of how a negative feedback loop works to maintain homeostasis diagram of simple reflex pathway diagram of negative feedback loop
1 A person with a fever walks outside on a cold day. Her body temperature drops from 100 F to 99 F. Instantly, mechanisms that increase body temperature are activated, including shivering. Yes, this is negative feedback. No, this is not negative feedback. 2 Calcium flows out of the sarcoplasmic reticulum in response to a muscle cell electrical impulse. The increased cytoplasmic calcium leads to muscle contraction. Yes, this is negative feedback. No, this is not negative feedback. 3 ATP is used during muscle contraction and the concentration of ATP in a muscle cell drops slightly. Cellular processes increase the level of ATP production so that cell ATP concentration returns toward normal. Yes, this is negative feedback. No, this is not negative feedback. 4 A sprinter stands motionless on the starting blocks before a 100 meter race. As the starter prepares to begin the race, the sprinter's heart rate starts increasing. Yes, this is negative feedback. No, this is not negative feedback.