Deck 15: Thermal Physiology

Question 1

Which of the following animals would be classified as a homeotherm?

A)polar fish
B)Burmese python
C)marine iguana
D)more than one of the above

Answer 1

A

Question 2

From among the following list of animals,which would lose heat at the fastest rate per unit mass?

A)bear
B)mouse
C)rabbit
D)wolf

Answer 2

B

Question 3

A __________ heterotherm can retain heat in certain parts of its body.

A)temporal
B)spatial
C)positional
D)regional

Answer 3

D

Question 4

__________ is essentially the ratio between reaction rates of a process adjusted for a 10°C temperature difference.

A)Q₁₀
B)An Arrhenius plot
C)Km
D)Homeoviscous adaptation

Question 5

Radiant heat from the body of an animal is described by

A)the Nernst equation.
B)the Stefan-Boltzmann equation.
C)Fourier's law.
D)Q₁₀.

Question 6

A(n)__________ cannot tolerate a wide ambient temperature range.

A)ectotherm
B)poikilotherm
C)eurytherm
D)stenotherm

Question 7

The __________ of a resting homeotherm is the range of ambient temperature where its metabolic rate is minimal.

A)thermoneutral zone
B)preferred temperature
C)optimal temperature range
D)idealized thermal region

Question 8

The exchange of thermal energy between an animal and its environment can occur by

A)conduction and convection.
B)radiation.
C)evaporation.
D)all of the above

Question 9

At which of the following systems would environmental temperatures be the most variable?

A)hydrothermal vents
B)cave systems
C)bathypelagic systems of the world's oceans
D)alpine terrestrial systems

Question 10

If the body temperature of an endothermic homeotherm falls below the __________ temperature,the metabolic rate increases.

A)upper critical
B)lower critical
C)incipient upper lethal
D)incipient lower lethal

Question 11

Which of the following is most synonymous with the term ectotherm?

A)heterotherm
B)poikilotherm
C)endotherm
D)pseudotherm

Question 12

Which one of the following has the highest thermal conductivity?

A)fat
B)air
C)water
D)rock

Question 13

According to Bergmann's and Allen's rules,brown bears living in temperate regions would be __________ than those living in the arctic.

A)larger with shorter limbs
B)smaller with shorter limbs
C)larger with longer limbs
D)smaller with longer limbs

Question 14

A __________ is an example of a temporal heterotherm.

A)python
B)swordfish
C)hummingbird
D)laminid shark

Question 15

Membrane fluidity can be increased by __________ of the plasma membrane.

A)increasing the lengths of fatty acid chains
B)decreasing the number of double bonds in the fatty acids
C)decreasing the phosphatidylcholine to phosphatidylethanolamine ratio
D)decreasing the cholesterol content

Question 16

In animals insulated with fur or feathers,__________ heat loss is reduced.

A)convective
B)conductive
C)radiant
D)more than one of the above

Question 17

Of the major classes of macromolecules,only __________ are substantially affected by temperature over the normal range experienced by animals.

A)proteins and lipids
B)carbohydrates
C)nucleic acids
D)all of the above

Question 18

In the process of homeoviscous adaptation,cells

A)alter rates of chemical reactions.
B)alter membrane fluidity.
C)alter isozyme ratios.
D)switch to alternative biochemical pathways.

Question 19

Some fish have the ability to keep certain parts of their body warm by the use of retia.Retia are

A)countercurrent heat exchangers.
B)found in locomotor muscles of certain species of large fish,such as tuna and lamnid sharks.
C)special adipose cells that generate heat.
D)A and B

Question 20

Temporal heterothermy

A)benefits ectotherms by enabling them to reach the thermoneutral zone.
B)benefits ectotherms by allowing them to increase their metabolism,which speeds up digestion,nutrient absorption,and biosynthesis.
C)benefits endotherms by enabling them to conserve energy when temperatures are cold.
D)B and C

Question 21

Ice crystals forming within tissues are detrimental due to the

A)piercing of cell membranes.
B)generation of hyperosmotic stress.
C)loss of membrane fluidity.
D)all of the above

Question 22

Typically,an endotherm has a resting metabolic rate that is __________ higher than that of an ectotherm of equivalent size.

A)2-fold
B)5-fold
C)10-fold
D)20-fold

Question 23

In some freeze-tolerant animals,intracellular ice crystal formation is prevented by the presence of

A)proton pumps.
B)antifreeze proteins.
C)heat shock proteins.
D)hydration elements.

Question 24

The antifreeze glycoproteins (AFGPs)share a common ancestry with

A)heat shock proteins.
B)pancreatic trypsinogen.
C)cytoskeletal actin.
D)Ca²⁺-dependent lectin.

Question 25

The mechanism by which bumblebees and certain moths generate preflight heat in thoracic muscles involves

A)a metabolic futile cycle in carbohydrate metabolism
B)the simultaneous contraction of antagonistic flight muscles.
C)rapid wing movement that avoids lift.
D)all of the above

Question 26

Organisms that thrive in the extreme cold are known as

A)psychrotrophs.
B)cryomorphs.
C)mesotrophs.
D)picnomorphs.

Question 27

In mice,the overexpression of a transcription factor PRDM16,results in an increase in BAT,which appears to be important

A)as an uncoupling protein.
B)in decreasing mitochondrial respiration.
C)in protection against metabolic dysfunctions,such as obesity.
D)in ATP production.

Question 28

BAT growth and thermogenesis are under the control of the

A)central nervous system.
B)sympathetic nervous system.
C)parasympathetic nervous system.
D)all of the above

Question 29

If the catalytic activity of an enzyme doubles with a biologically relevant 10°C increase in temperature,then Q₁₀ would be near the value of

A)2)
B)5)
C)10.
D)20.

Question 30

The observation that a given enzyme retains its kinetic properties in different species adapted to different temperature regimes is a phenomenon known as

A)Arrhenius effect.
B)Q₁₀.
C)conservation of Km.
D)homozyme stability.

Question 31

Most thermogenic pathways of futile cycling involve cycling between the hydrolysis and synthesis of

A)heat shock proteins.
B)fatty acids.
C)glucose-6-phosphate.
D)ATP.

Question 32

Shivering thermogenesis of many birds and mammals is associated with

A)white adipose tissue.
B)cardiac muscle tissue.
C)brown adipose tissue.
D)skeletal muscle tissue.

Question 33

In brown adipose tissue,thermogenin inserts into the inner mitochondrial membrane and serves to

A)uncouple oxidation from phosphorylation.
B)enhance the proton motive force.
C)eliminate two of the steps of electron transport.
D)more than one of the above

Question 34

Cold-adapted enzymes are more efficient at low temperatures than their warm-adapted counterparts due to their

A)increased stability.
B)reduction in weak bonds that stabilize the three-dimensional structures.
C)higher proportion of hydrogen bonds.
D)more than one of the above

Question 35

Temperature-dependent remodeling may involve qualitative strategies such as

A)changes in mitochondrial density of muscle fibers.
B)hypertrophic growth of the heart.
C)seasonal differential expression of myosin isoforms.
D)variable levels of myoglobin concentrations.

Question 36

The ability to produce endogenous body heat is known as

A)metabolic hyperthermy.
B)mesothermy.
C)thermogenesis.
D)oxidative metabolism.

Question 37

__________ have lost the ability to mount a heat shock response.

A)Antarctic fish
B)Fruit flies
C)Reindeer
D)Bluefin tuna

Question 38

During times of thermal stress,heat shock proteins act as

A)chaperones to assist in the refolding of proteins.
B)transcriptional activators that ultimately lead to altered membrane lipids.
C)intercellular cytokine messengers that trigger adaptive responses in adjoining cells.
D)more than one of the above

Question 39

To date,__________ classes of antifreeze proteins have been identified.

A)2
B)3
C)4
D)5

Question 40

__________ are able to survive without expressing functional myoglobin.

A)Coral reef damsel fish
B)Salmon
C)Polar bears and other arctic mammals
D)Antarctic fish

Question 41

A __________ heterotherm can retain heat in certain parts of the body.

Question 42

Thermogenic pathways rely on __________ cycling in which chemical potential energy is spent to generate heat.

Question 43

Many animals exhibit a daily hypometabolic state known as

A)estivation.
B)endothermy.
C)hibernation.
D)torpor.

Question 44

In animals,regulating how much blood flows into the vasculature is referred to as the _____________ response.

Question 45

The central thermostat of birds appears to reside in the

A)atrial wall.
B)adrenal cortex.
C)hypothalamus.
D)spinal cord.

Question 46

What is the primary role of salt as a constituent of sweat in evaporative cooling systems?

A)boiling point elevation
B)water balance
C)blood pressure regulation
D)electrolyte adjustment

Question 47

__________ is the ability to generate and maintain elevated body temperatures.

Question 48

The reduction of heat loss via piloerection is a phenomenon commonly observed in

A)birds and mammals.
B)heterothermic fish.
C)large flying insects.
D)marine reptiles.

Question 49

A __________ is an animal with a body temperature that varies in response to environmental conditions.

Question 50

Typically located near the backs and shoulders,__________ tissue is particularly important for thermogenesis in small mammals and newborns of larger mammals.

Question 51

The use of skeletal muscles to generate heat in birds and mammals is referred to as __________.(two words)

Question 52

The relatively constant temperature of the deep,internal region of a homeotherm is known as the __________ temperature.

Question 53

Cells can remodel their membranes to preserve fluidity in a process known as __________ adaptation.

Question 54

__________ are animals that thrive in the extreme cold.

Question 55

What do the red muscles of tuna,the optical systems of billfish,and the legs of birds have in common?

A)higher proportions of glycolytic muscle fibers
B)brown adipose tissue
C)countercurrent heat exchangers
D)more than one of the above

Question 56

In biological systems,radiant heat exchange occurs through electromagnetic radiation in the __________ range.

Question 57

The independent routes to endothermy of birds and mammals can be explained by the ________________evolution of insulation.

Question 58

The range of __________ is the difference between the incipient upper and lower lethal temperatures.

Question 59

As compared to cooler regions,in the warmer regions of their habitats,reindeer are able to reduce body temperature more effectively by

A)breathing through their nostrils.
B)increasing the rates of evaporative cooling from their ears.
C)switching to glycolysis in their brain stems.
D)panting and increasing the breathing frequency.

Question 60

In the natural world,the complex response of an animal to seasonal changes in temperature is known as __________.

Question 61

What are the four mechanisms by which cells can remodel membranes to preserve fluidity?

Question 62

Citing two examples,explain how an animal can alter its surface area to volume ratio to reduce heat loss?

Question 63

Describe the molecular events of the heat shock response involving Hsp70.

Question 64

What is BAT and what role does it play in animal physiology?

Question 65

Describe how birds and mammals lose heat through ventilation.

Question 66

Name and briefly define the four routes by which heat is transferred between an animal and its environment.

Question 67

The raising of individual hairs in mammals to increase the insulation capacity of the fur is a process known as __________.

Question 68

Describe the three preflight mechanisms of regional heterothermy observed in bumblebees and large flying moths.

Question 69

Describe the vasomotor response observed in the skin of animals.

Question 70

__________ is a cooling behavior seen in birds and is characterized by rapid contraction and relaxation of throat muscles.

Question 71

How have selective pressures altered the expression of the LDH-B gene among populations of killifish living along the eastern coast of North America?