Question 1

Which of the following best describes the main difference between a regulator and a conformer in terms of thermoregulation?

Accepted Answer

A regulator maintains a constant internal temperature regardless of external conditions, while a conformer allows its internal temperature to vary with the environment.

Question 2

A lizard is observed basking on a sun-warmed rock in the morning and retreating to the shade during midday. Which heat transfer mechanisms are primarily involved in these behaviors?

Accepted Answer

Radiation and conduction

Question 3

Which of the following is an example of counter-current heat exchange in animals?

Accepted Answer

Arterial blood flowing toward a goose's foot transfers heat to venous blood returning to the body, keeping the core warm.

Question 4

Which adaptation would you expect to find in an animal living in the Arctic to minimize heat loss?

Accepted Answer

Thick fur and a low surface-area-to-volume ratio

Question 5

A human infant is exposed to cold temperatures. Which mechanism is most likely to be activated to generate heat?

Accepted Answer

Non-shivering thermogenesis in brown adipose tissue

Question 6

Which equation correctly represents the scaling of basal metabolic rate (BMR) with body mass ($$M) in $$mammals?

Accepted Answer

$$BMR \propto M$$^{3/4}$$

Question 7

Why do small mammals like shrews have higher mass-specific metabolic rates compared to large mammals like elephants?

Accepted Answer

They lose heat more rapidly due to a higher surface-area-to-volume ratio and must generate more heat per unit mass.

Question 8

Which of the following best explains why a jack rabbit has large ears?

Accepted Answer

To increase surface area for heat loss via radiation and convection

Question 9

During hibernation, an arctic ground squirrel’s body temperature drops close to the ambient temperature. This is an example of:

Accepted Answer

Endothermic-heterothermy

Question 10

Which process is the primary method of heat loss in humans during vigorous exercise on a hot day?

Accepted Answer

Evaporation of sweat

Question 11

A turtle moves from cold water to a sunlit log to warm up. Which type of thermoregulation is this an example of?

Accepted Answer

Behavioral thermoregulation

Question 12

Which of the following statements about insulation is correct?

Accepted Answer

Insulation works by trapping air, which is a poor conductor of heat, thereby reducing heat loss.

Question 13

Which physiological response would a mammal most likely use to conserve heat in a cold environment?

Accepted Answer

Peripheral vasoconstriction

Question 14

A kangaroo in the Australian desert licks its forearms during the hottest part of the day. What is the primary benefit of this behavior?

Accepted Answer

Evaporative cooling of blood in the forearms

Question 15

Which of the following best describes non-shivering thermogenesis?

Accepted Answer

Heat production in brown adipose tissue where mitochondrial respiration is uncoupled from ATP synthesis

Question 16

Which of the following is NOT a mechanism of heat transfer used by animals to regulate body temperature?

Accepted Answer

Photosynthesis

Question 17

If a mammal’s set point for body temperature is exceeded, which of the following responses is most likely to occur?

Accepted Answer

Sweating and peripheral vasodilation

Question 18

Which of the following best explains why aquatic mammals like dolphins have counter-current heat exchangers in their fins?

Accepted Answer

To minimize heat loss to cold water by transferring heat from arteries to veins before blood reaches the extremities

Question 19

Which of the following is a correct sequence for the homeostatic control of body temperature in mammals?

Accepted Answer

Stimulus → Sensor → Control center → Effector → Response

Question 20

Which of the following best describes the circadian rhythm of body temperature in humans?

Accepted Answer

Body temperature decreases at night as melatonin peaks and increases in the morning as melatonin declines.

CHAPTER 32

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