Which of the following best describes how the body maintains a stable internal temperature when the external environment becomes very cold?

• The body increases sweat production to cool down.

• The body constricts blood vessels near the skin and shivers to generate heat.

• The body increases heart rate to pump more blood.

• The body decreases hormone production.

Which hormone is primarily responsible for lowering blood glucose levels in the body?

• Glucagon

• Insulin

• Adrenaline

• Thyroxine

What is the main function of negative feedback mechanisms in the endocrine system?

• To amplify changes in the body

• To maintain homeostasis by reversing deviations from a set point

• To speed up metabolic reactions

• To increase hormone production indefinitely

Which of the following is an example of an internal factor that can disrupt homeostasis?

• Sudden drop in outside temperature

• Infection causing a fever

• Loud noises

• Bright sunlight

Which of the following best describes a feedback mechanism involved in blood glucose regulation?

• Positive feedback increases insulin release when glucose is low.

• Negative feedback decreases insulin release when glucose is low.

• Positive feedback decreases glucagon release when glucose is high.

• Negative feedback increases glucagon release when glucose is high.

A student investigates the effect of exercise on body temperature. After 20 minutes of running, the student’s temperature rises. Which feedback mechanism is most likely to be activated to restore homeostasis?

• Positive feedback to increase temperature further

• Negative feedback to promote sweating and vasodilation

• Negative feedback to decrease sweating

• Positive feedback to decrease temperature

You are given data showing blood glucose levels before and after a meal. How would you use this data to draw a conclusion about the effectiveness of insulin in maintaining homeostasis?

• Compare the levels and see if glucose returns to normal after insulin is released.

• Ignore the data and make a guess.

• Only look at the highest glucose level.

• Focus on the time of day instead of glucose levels.

A group of students conducts an experiment to test the effect of cold water immersion on body temperature. Which conclusion is best supported if their data shows a rapid drop in skin temperature followed by stabilization?

• The body cannot regulate temperature.

• Homeostatic mechanisms, such as vasoconstriction, help stabilize internal temperature.

• Hormones are not involved in temperature regulation.

• The experiment was invalid.

If a person’s pancreas fails to produce insulin, what would you predict happens to their blood glucose levels after eating a meal?

• Blood glucose levels would decrease rapidly.

• Blood glucose levels would remain high.

• Blood glucose levels would not change.

• Blood glucose levels would drop below normal.

A student is asked to communicate the results of an investigation on hormone levels during stress. Which method would be most effective?