Chapter 10 Quiz

. All animals produce heat but only some are endothermic. This is because

only endotherms produce heat fast enough or retain it well enough to elevate tissue temperatures.

ectotherms are too small to be endothermic.

ectotherms cannot thermoregulate.

thermoregulation requires endothermy.

. If a 3800-kg elephant and a 20-g mouse both have body temperatures of 37°C, which statement would be true?

The temperatures of the animals and the amount of heat they contain are similar but different.

Both animals have the same temperature and contain the same amount of heat.

Both animals have the same temperature but contain different amounts of heat.

Both animals have the same temperature but the average molecular speed inside the mouse is faster.

. What is the key distinction between conduction and convection?

In conduction, the atoms of the substance participate in transfer of heat, but in convection they do not.

In convection, the atoms of the substance participate in transfer of heat, but in conduction they do not.

Convection involves heat transfer through macroscopic motion.

Conduction involves heat transfer through macroscopic motion.

. H_{radiative emission}= ε σ T_surface⁴is known as

the heat balance equation.

Bergmann's rule.

the second law of thermodynamics.

the Stefan-Boltzmann equation.

. The effects of animal coloration on heat balance are

greater at night.

greater in sunlight.

unaffected by sunlight.

primarily via convection.

. Compared to light-colored animals, dark-colored animals absorb _______ short wavelength radiation and _______ longer wavelength radiation.

more; less

less; more

about the same amount of; more

more; about the same amount of

. An animal that can function effectively over a wide range of temperatures and cannot elevate its tissue temperature above the environmental temperature is a

stenothermal poikilotherm.

stenothermal endotherm.

eurythermal endotherm.

eurythermal poikilotherm.

. As environmental temperature increases, a poikilotherm's metabolic rate

stays the same if it is within its thermoneutral zone.

increases linearly.

increases exponentially.

can either increase or decrease, depending on the species.

. If metabolic rate (M) were a true exponential function of the body temperature (T_B) of an ectotherm, which equation would describe that relationship? (Assume that a and n are constants for each data set.)

M = a·10ⁿ^·^T_^B

T_B = aMⁿ

M = aT_B^10·ⁿ

T_B = aM^10·ⁿ

. Some Antarctic molluscs die of heat stress if their body temperature rises above 2°C and some tropical molluscs die of cold stress if cooled to 4°C. This comparison illustrates

the phenomenon of acclimation.

the phenomenon of acclimatization.

the phenomenon of evolutionary specialization.

that the pejus temperature for molluscs is about 3°C.

. Why do the eyes of cows and soldierfish get cold cataracts at low temperatures, while the lenses of the Antarctic toothfish stay clear?

Toothfish are acclimatized to cold; cows and soldierfish are not.

The chemical structure of the crystalline proteins of the toothfish differ from that of the cow and the soldierfish.

Toothfish have tissues that serve as heaters to keep their eyes warm in cold water; the cow and the soldierfish do not.

Toothfish are eurythermal; the cow and soldierfish are stenothermal.

. If the temperature of the oceans increased by 4°C, which organism would likely be most affected?

Pagothenia (an Antarctic genus of fish)

The mullet (a warm water fish)

Temperate water gobies

A very eurythermal fish

. Animals from numerous habitats tend to have relatively similar membrane fluidities when they are living at their respective, normal body temperatures. The relative constancy of membrane fluidity regardless of tissue temperature is called

lipid stabilization.

saturation dynamics.

bilayer constancy.

homeoviscous adaptation.

. Homeothermy is

the regulation of body temperature by physiological means.

the regulation of body temperature through behavior.

the regulation of metabolic rate within the thermal neutral zone.

equal to basal metabolic rate plus external work.

. As a mammal experiences an increase in ambient temperature from the lower critical temperature to the upper critical temperature, its body temperature _______, metabolic rate _______, and thermal conductance _______.

increases; increases; increases

increases; is relatively constant; decreases

is relatively constant; is relatively constant; decreases

is relatively constant; is relatively constant; increases

. Which mechanism is used by mammals, but not birds, to ameliorate heat stress at temperatures above thermoneutrality?

Shivering

Sweating

Gular fluttering

Panting

. In the studies of Hill et al., the ear temperatures of resting jackrabbits were at about 8°C when air temperature was 8°C. Immediately after running, the rabbits registered ear temperatures higher than 30°C, but in less than 30 minutes the temperatures had returned to about 8°C. What is the likely reason for the increase in ear temperature during running?

An increase in radiative heat gain by the ears

An increase in convective heat gain by the ears

Dissipation of excess metabolic heat produced during running

Retention of body heat during exercise

. During a bout of fever in a placental mammal, _______ of cutaneous vascular beds are activated when the set point of the thermoregulatory control system is above body temperature. When the set point of the thermoregulatory control system is below body temperature, _______ of cutaneous vascular beds are activated.

sweating and vasodilation; shivering and vasoconstriction

sweating and vasoconstriction; shivering and vasodilation

shivering and vasodilation; sweating and vasoconstriction

shivering and vasoconstriction; sweating and vasodilation

. In a limb, a countercurrent flow arrangement of arteries and veins short-circuits the flow of _______ down its length.

heat

oxygen

nutrients

waste products

. Antelope ground squirrels are diurnally active rodents that live in hot deserts. In summer, they alternate between trips above-ground and trips down to their cooler burrows. When they are above-ground their body temperature temporarily rises (transient hyperthermia). This most likely

conserves energy.

conserves water.

occurs because they are not capable of thermoregulation.

allows them to bring heat back down into the burrows to warm their young.

. Countercurrent heat exchange is important in the _______ of a warm-bodied fish.

backbone

gills

red swimming muscles

white swimming muscles

Chapter 10 Quiz

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