130
Energy Balance and Thermal Physiology
A. Multiple Choice
Key/
Page
No.
716
a. Energy is subject to an input-output balance similar to that for water.
b. An example of internal work is the energy expended by muscles to lift a heavy
object.
c. Almost 75% of nutrient energy is lost as heat and not used to do work.
d. Energy is normally expressed in terms of heat energy.
e. none of these.
716,
719
a. chemical energy in ATP and kinetic energy of locomotion
b. standard metabolic rate and resting metabolic rate
c. basal metabolic rate and thermal neutral zone
d. field metabolic rate and average metabolic expenditure over time
e. endotherms and amphibians
720
a. are measured during periods of aerobic activity.
b. involve the use of treadmills.
c. are an indicator of an animal’s activity capacity.
d. are the ratio of metabolic rate to SMR.
e. two of these.
722
a. results from an increase in metabolic activity associated with processes occurring
in the gut.
b. is the increase in heat production that occurs after a meal
c. has historically been studied in endotherms.
d. is affected by the amount of food an animal consumes.
e. all of these.
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717
a. is the generation of heat to compensate for sudden weight loss associated with
dieting.
b. is an increase in metabolic rate due to the energy expenditures associated with
feeding and digestion.
c. is the generation of heat associated with “fat-burning” diets.
d. offsets the energy expenditures associated with SMR and BMR.
e. involves both internal and external work.
719
d
The minimal metabolic activity required to maintain bodily functions in a mammal is
a. ectothermic.
b. endergonic.
c. exergonic.
d. endothermic.
e. homeothermic.
719
known as the
a. resting metabolic rate.
b. standard metabolic rate.
c. minimal metabolic rate.
d. basal metabolic rate.
e. none of these.
720
can be explained by
a. their larger size which means they have more surface area for absorbing radiant
energy, so they require less metabolic energy to stay warm.
b. their larger size which makes them less susceptible to predation, so they don’t
have to use energy to escape from predators.
c. their greater weight which makes them less inclined to move, so they expend less
energy in locomotion.
d. their lower surface to volume ratio which means they lose a lesser percentage of
their energy to the environment.
e. none of these.
717
Einput-Eloss= EBMR+Eproduction+Eactivity+EDIT.
In this equation, Eloss refers to
a. thermal energy given off as a consequence of the first law of thermodynamics.
b. thermal energy given off as a consequence of the second law of thermodynamics.
c. thermal energy given off as a consequence of dietary intake.
d. potential energy given off in the form of undigested foodstuffs (feces), sloughed
skin, hair or other body products.
e. none of these.
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717
would most like to ________ is ________.
a. decrease; EBMR
b. decrease; Eloss
c. decrease; Eproduction
d. increase; Eproduction
e. increase; Einput
729
a. uncoupling electron transport in mitochondria from ATP production.
b. uncoupling glycolysis from ATP production.
c. uncoupling food intake from nutrient uptake in the gut.
d. all of these.
e. none of these.
d
BMR
720
a. is regulated by thyroid hormones.
b. is affected by bile acids.
c. is affected by the amount of fat in the diet.
d. all of these.
724
a. sexual intercourse
b. bicycling on a level surface
c. swimming
d. jogging
e. walking up stairs
e
Ghrelin and obestatin
728
a. are secreted by the digestive tract.
b. arise from the same gene.
c. arise from the same protein.
d. are secreted by the digestive tract and arise from the same gene.
e. all of these.
728
a. cholecystokinin (CCK)
b. ghrelin
c. corticotropin releasing hormone
d. PYY3-36
e. insulin
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726
appetite.
a. –MSH; stimulate
b. –MSH; suppress
c. melanocortin; stimulate
d. melanocortin; suppress
e. none of these.
731
chains in the plasma membranes of its cells?
a. arctic fish
b. penguins
c. polar bears
d. tropical fish
e. pelicans
732
temperatures. This is due to the fact that
a. in poikilothermic organisms, muscles must function over a broad range of
temperatures, and myosin ATPase activity is essential for muscle function.
b. at lower temperatures, myosin can uncouple from actin, and the ATPase activity
can be used to generate heat without locomotion, allowing the lizard to warm up
metabolically.
c. both of these.
d. neither of these.
733
to maintain their body temperature when they are losing heat to the environment.
a. ectothermic
b. endergonic
c. poikilothermic
d. endothermic
e. homeothermic
734
loss because
a. the large surface to volume ratio of the ear favors loss of heat to the environment.
b. the flapping favors heat loss by conduction.
c. the flapping favors heat loss by convection.
d. the flapping favors heat loss by evaporation.
e. all of these.
b
Leptin stimulates the hypothalamus to secrete ________, which in turn acts to _____
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734
likely due to heat loss through
a. conduction.
b. convection.
c. evaporation.
d. radiation.
e. metabolism.
739
c
Which of the following statements is NOT true?
water freezes.
a. 25%
b. 45%
c. 50%
d. 65%
e. 80%
733,
737
a. Some ectotherms can regulate their body temperature as efficiently as a mammal.
b. Ectothermic regulators may also be poikilotherms.
c. Endotherms gain all their heat from internal, biochemical reactions.
d. Some poikilotherms are homeotherms.
e. None of these.
739
glycogen and release glucose into the blood, which can then be taken up into cells. This
provides a benefit to the frog in that
a. plasma glucose acts as a cryoprotectant by lowering the freezing point of the
extracellular fluid.
b. cellular glucose acts as a cryoprotectant by lowering the freezing point of the
intracellular fluid.
c. cellular glucose is readily available for glycolysis once the frog thaws.
d. all of these.
e. none of these.
739
a. lower the freezing point of plasma due to their colligative properties.
b. raise the melting point of plasma ice due to their colligative properties.
c. nucleate the formation of ice crystals in the extracellular fluid.
d. interact with ice crystals to prevent their growth.
e. none of these.
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740
a. are also known as stress proteins.
b. are hydrophobic proteins.
c. are attracted to hydrophobic amino acids normally located on the inside of folded
proteins.
d. are also called molecular chaperones.
e. all of these.
743
a. increasing the amount of air trapped next to the skin.
b. increasing the absorption of radiant energy from the sun.
c. increasing the insulation provided by subcutaneous fat.
d. reducing heat loss by restricting blood flow to the skin.
743
a. generating heat through the metabolic activity of the vascular musculature.
b. causing piloerection, which increases the amount of air (a poor thermal conductor)
trapped next to the skin.
c. directing blood away from the body surface, avoiding the transfer of heat from the
blood to the environment.
d. causing the skin of the animal to blanch, increasing the ability of radiant energy to
penetrate to the animal’s core.
e. none of these.
734,
738
of thermogenesis is
a. shivering increases ATP use and heat production without increasing heat loss due
to convection.
b. with shivering all the energy expended is released as heat since no work is done.
c. shivering increases ATP use and heat production without increasing heat loss due
to conduction.
d. shivering increases ATP use and heat production without increasing heat loss by
either convection or conduction.
e. all of these.
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therefore they will want to
a. avoid heat loss by evaporative cooling and instead employ heat storage
mechanisms to deal with heat stress.
b. avoid heat loss by evaporative cooling and instead burrow to seek cooler
microclimates.
c. avoid heat loss by evaporative cooling and instead restrict their activity to night
when ambient temperatures are cooler.
d. avoid heat loss by entering into extended periods of sleep and inactivity during
the summer (estivation) which is similar to hibernation by some animals in the
winter.
e. avoid heat loss by evaporative cooling by burrowing and restricting activity to
times with cooler temperatures.
747
a. permits convective currents to carry heat away from the body surface.
b. permits exchange of air with 100% humidity for air with lower humidity, enabling
evaporative cooling to occur.
c. both of these.
d. neither of these.
748
c
33.
In birds, the hypothalamus does not
a. range of environmental temperatures when the animal does not need to expend
large amounts of energy on thermoregulation.
b. the body temperatures which an animal maintains while at its basal metabolic
rate.
c. the range in environmental temperatures where mechanisms involving insulation
are sufficient.
d. two of these.
e. all of these.
748
a. stimulate shivering.
b. stimulate panting.
c. stimulate erection of plumage.
d. none of these.
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environment is called the
a. lower critical temperature.
b. critical neutral temperature.
c. upper critical temperature.
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750
a. is a hypothalamic response to pyrogens released by white blood cells.
b. is a pathological response to combat infections.
c. is a poorly understood mechanism to fight disease.
d. two of these.
e. all of these.
750
a. ectotherms in certain parts of their range and endotherms in other parts of their
range.
b. endotherms that only practice thermogenesis in certain strata of their habitat.
c. endothermic, but only in specific tissues of their body.
d. two of these.
e. all of these.
751
the hibernation period. It is thought that this is because
a. they need to void wastes.
b. they need to eat a little to restore glycogen stores, especially in their brains.
c. they need to rewarm to activate their immune systems in case they’ve become
infected.
d. two of these.
e. all of these.
719
a. at the optimal temperature for the organism.
b. during sleep.
c. with diet-induced thermogenesis subtracted from the final value.
d. two of these.
e. all of these.
a
For running mammals
721
a. the increase in metabolism is roughly linear with velocity.
b. the increase in metabolism is inversely related to velocity.
c. the increase in metabolic rate is independent of velocity.
753
a. have no hair.
b. produce young parthenogenically.
c. don’t nurse their young.
d. are ectothermic.
e. don’t regulate body mass.
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B. True or False
716 environment becomes disorganized.
720
726 energy.
740 cells.
725
717
719
732
736 maintain a relatively stable body temperature.
744
C. Matching (correct answers are aligned with each number; e.g., #1 matches with letter a)
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D. Essay
Page No.
why the respiratory quotient (ratio of the volume of CO2 produced per volume O2
consumed) is higher for the former than the latter.
751
optimum.
Explain why activity increases as temperature rises, reaches a maximum, and then
decreases. What is the evolutionary/adaptational significance of the temperature
optimum?
725
745 temperature.
747 contrast shivering and other muscle activity with nonshivering (chemical) thermogenesis
as a means of generating body heat.