Question 1

Which of the following best describes homeothermy?

Accepted Answer

Maintaining a constant, high body temperature regardless of environmental temperature

Question 2

What is the primary physiological mechanism by which homeotherms generate heat?

Accepted Answer

Metabolic reactions within mitochondria

Question 3

Which tissue is specialized for non-shivering thermogenesis in mammals?

Accepted Answer

Brown adipose tissue (BAT)

Question 4

Why is homeothermy considered energetically expensive?

Accepted Answer

Over 90% of energy consumed is converted directly into heat to maintain body temperature

Question 5

Which of the following is a benefit of homeothermy?

Accepted Answer

Stable thermal environment for enzymes

Question 6

What is the function of uncoupling proteins in mitochondria?

Accepted Answer

Allow protons to leak across the inner membrane, generating heat instead of ATP

Question 7

Which equation best represents the relationship between metabolic rate (MR) and body mass (M) in mammals?

Accepted Answer

$$MR = a 	imes M$$^{0.75}$$

Question 8

During hibernation, what happens to the metabolic rate and body temperature of a homeotherm?

Accepted Answer

Both metabolic rate and body temperature drop significantly

Question 9

Which adaptation helps reduce the energetic cost of homeothermy in cold environments?

Accepted Answer

Insulation, such as fur or blubber

Question 10

What is the main difference between ectotherms and endotherms?

Accepted Answer

Ectotherms absorb heat from the environment; endotherms produce heat metabolically

Question 11

Which of the following statements about mass-specific metabolic rate is correct?

Accepted Answer

Smaller animals have higher mass-specific metabolic rates than larger animals

Question 12

How do hummingbirds conserve energy during periods of inactivity?

Accepted Answer

By entering daily torpor, reducing metabolic rate and body temperature

Question 13

Which of the following is NOT a characteristic of homeotherms compared to poikilotherms?

Accepted Answer

Lower concentrations of metabolic enzymes

Question 14

What is the role of shivering in thermoregulation?

Accepted Answer

Generates heat through low amplitude muscle contractions

Question 15

Which of the following best explains why an elephant consumes more total oxygen per hour than a shrew, but has a lower mass-specific metabolic rate?

Accepted Answer

Metabolic rate scales with body mass, but mass-specific metabolic rate decreases as size increases

Question 16

Which of the following is a real-world example of behavioral thermoregulation?

Accepted Answer

A lizard basking in the sun to raise its body temperature

Question 17

Which process is most likely suppressed during hibernation to reduce metabolic rate?

Accepted Answer

Electron transport chain (ETC) activity in mitochondria

Question 18

Which of the following animals is most likely to use brown adipose tissue (BAT) for arousal from hibernation?

Accepted Answer

A hibernating mammal

Question 19

Which of the following best describes the thermal neutral zone (TNZ) in homeotherms?

Accepted Answer

The range of environmental temperatures where metabolic rate is minimal and body temperature is maintained without extra energy expenditure

Question 20

Which of the following statements about poikilotherms is correct?

Accepted Answer

Poikilotherms tend to be ectotherms and allow their body temperature to fluctuate with the environment

Homeothermy, Endothermy, and Animal Metabolic Strategies

Study Guide - Practice Questions