Free Homeostasis MCQs with Answers
62 Homeostasis MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
62 questions · page 7 of 7
61. A person in hot weather is unable to maintain body temperature. Which physiological process has failed?
- A. Vasodilation & sweating
- B. Vasoconstriction
- C. Shivering
- D. Renin secretion
Explanation: Cooling in hot conditions depends on dilating the skin arterioles so more warm blood reaches the surface and on evaporating sweat, which draws latent heat from the skin. Vasoconstriction and shivering are the responses to cold, so their failure would show in the opposite conditions. Renin controls blood pressure and sodium balance rather than temperature.
Correct answer: Vasodilation & sweating62. Which of the following organisms eliminate nitrogenous waste mainly in the form of uric acid?
- A. Freshwater Fish
- B. Amphibians
- C. Birds
- D. Mammals
Explanation: Uric acid is almost insoluble, so it can be excreted as a paste with very little water, which suits birds both for flight and for developing inside a shelled egg where waste must be stored safely. Freshwater fish excrete ammonia directly into the surrounding water, and mammals and adult amphibians make urea. The choice of waste product tracks how much water the animal can afford to lose.
Correct answer: Birds