Deck 40: Physiology, Homeostasis, and Temperature Regulation

Question 1

Which type of tissue is responsible for secreting digestive enzymes?

A) Connective
B) Epithelial
C) Matrix
D) Muscle
E) Nervous

Answer 1

Epithelial

Question 2

Although there are many kinds of specialized cell types, there are only _______ kinds of tissues.

A) 1
B) 14
C) 4
D) 3
E) 6

Answer 2

4

Question 3

If the Q₁₀ of the metabolic rate of an animal is 2, then

A) the animal is better acclimatized to a cold environment than if its Q₁₀ is 3.
B) the animal is an ectotherm.
C) the animal consumes half as much oxygen per hour at 20°C as it does at 30°C.
D) the animal's metabolic rate is not at basal levels.
E) the animal produces twice as much heat at 20°C as it does at 30°C.

Answer 3

C

Question 4

Which of the following is not a type of muscle tissue?

A) Cardiac
B) Connective
C) Smooth
D) Skeletal
E) All of the above are types of muscle tissue.

Question 5

What is the biggest difference between a "cold" fish such as a trout and a "hot" fish such as a tuna?

A) The temperature of the blood leaving the heart
B) The temperature of the blood entering the gills
C) The arrangement of blood vessels in the gills
D) The temperature of the brain
E) The volume of blood flowing in arteries just under the skin

Question 6

In regulatory systems, the phenomenon of negative feedback

A) is the least common type of feedback mechanism.
B) stimulates a return to set point.
C) amplifies a response.
D) disrupts homeostasis.
E) None of the above

Question 7

Which of the following would serve to increase the set point of a regulatory system?

A) Negative feedback
B) Positive feedback
C) Feedforward information
D) Insensitivity to information
E) None of the above

Question 8

Which of the following would cause a decrease in the hypothalamic temperature set point for metabolic heat production?

A) Entering a cold environment
B) Taking an aspirin when you have a fever
C) Arousing from hibernation
D) Getting an infection that causes a fever
E) Cooling the hypothalamus

Question 9

Mammalian hibernation

A) occurs when animals run out of metabolic fuel.
B) is a regulated decrease in body temperature.
C) is less common than hibernation in birds.
D) can occur at any time of year.
E) lasts for several months, during which body temperature remains close to the environmental temperature.

Question 10

Suppose an airline pilot sets an aircraft's engines to produce a speed of 450 mph, and measures that speed using an instrument on the outside of the plane. When another pilot reports turbulence ahead, the pilot changes the set point to 350 mph. The other pilot is providing

A) an error signal.
B) negative feedback.
C) positive feedback.
D) feedforward information.
E) homeostasis.

Question 11

Positive feedback responses

A) are long-term, stable influences in the body.
B) can increase or decrease the deviation from a set point.
C) are more common than negative feedback responses.
D) tend to reach a limit and then terminate.
E) cause physiological parameters to cycle above and below a set point.

Question 12

Which of the following statements about the thermoneutral zone is true?

A) Metabolic heat production is variable.
B) Skin blood flow is variable.
C) The environmental temperature equals body temperature.
D) The lower boundary (lower critical temperature) is lower for small than for large endotherms.
E) It is the range of hypothalamic temperatures that do not alter metabolic heat production.

Question 13

Homeostasis refers to the tendency to keep body systems

A) matched to the external environment.
B) the same relative to one another.
C) in a steady state over time.
D) under the control of the brain.
E) at the same specific temperature.

Question 14

Which of the following characterizes the protein elastin?

A) It functions predominantly in muscle tissue to resist excess stretching.
B) It is found predominantly in epithelial tissue.
C) It is found in the extracellular matrix of connective tissue.
D) It is the most abundant protein in the body.
E) It is responsible for the elasticity of the long extensions of neurons.

Question 15

Which of the following is the most important and most general characteristic of endotherms adapted to cold climates compared with those adapted to warm climates?

A) Higher basal metabolic rates
B) Higher Q₁₀ values
C) Brown fat
D) Greater insulation
E) Ability to hibernate

Question 16

Which of the following is an important difference between an ectotherm and an endotherm of similar body size?

A) An ectotherm has higher Q₁₀ values.
B) Only an ectotherm uses behavioral thermoregulation.
C) Only an endotherm can constrict and dilate the blood vessels to the skin to alter heat flow.
D) Only an endotherm can have a fever.
E) At a body temperature of 37°C, an ectotherm has a lower metabolic rate than an endotherm.

Question 17

Which of the following tissue types is likely to be found at any boundary where the inside of the body meets the external environment?

A) Nervous
B) Epithelial
C) Muscle
D) Connective
E) Striated

Question 18

How would you describe the role of skin temperature in the human thermoregulatory system?

A) It provides feedforward information.
B) It acts as a set point for metabolic heat production.
C) It provides positive feedback information.
D) It provides an error signal.
E) It provides negative feedback information.

Question 19

Which statement about brown fat is true?

A) It produces heat without producing ATP.
B) It insulates animals acclimatized to cold.
C) It is a major source of heat production for birds.
D) It is found only in hibernators.
E) It provides fuel for muscle cells.

Question 20

Which of the following statements about positive feedback is false?

A) It is more commonly observed than negative feedback.
B) It tends to reach a limit and terminate rapidly.
C) It amplifies a response.
D) Contractions of the uterus are an example of positive feedback.
E) Sexual behavior is an example of positive feedback.

Question 21

Most physiological processes

A) occur more rapidly at higher temperatures.
B) occur less rapidly at higher temperatures.
C) are not temperature sensitive.
D) maintain a constant rate as temperature increases.
E) None of the above

Question 22

Most biological Q₁₀ values are between _______ and _______.

A) 0; 1
B) 1; 2
C) 2; 3
D) 2; 10
E) 0; 40

Question 23

Environmental temperature influences the body tem­perature of many animals, especially those that live in _______ environments.

A) cave
B) urban
C) aquatic
D) terrestrial
E) mountaintop

Question 24

The first cool breeze of autumn is at a temperature that will feel warm in the middle of winter because

A) day length influences one's sensation of temperature.
B) winter breezes are weaker than those in autumn.
C) nerve cells of the skin die off during winter.
D) we acclimatize to temperature.
E) None of the above

Question 25

Which of the following Q₁₀ values indicates that a reaction is not temperature sensitive?

A) 1
B) 2
C) 3
D) 8
E) 10

Question 26

The upper temperature limit at which cells can function is determined by the

A) boiling point of water.
B) melting point of water.
C) melting point of fats.
D) denaturation point of nucleic acids.
E) denaturation point of proteins.

Question 27

One function of adipose tissue is

A) in thermoregulation.
B) to store genetic material.
C) electrical signal transmission.
D) to provide support against gravity.
E) to transport oxygen.

Question 28

The reactions that comprise animal metabolism are not equally sensitive to temperature. Which of the following values reflects that fact?

A) $\Delta$ K
B) O_2max
C) V₂
D) Molecular weight
E) Q₁₀

Question 29

Connective tissues differ from one another mostly in their

A) cellular structure.
B) function in support.
C) matrix composition and properties.
D) location in the body.
E) cell packing.

Question 30

Most cellular functions are limited to a temperature ranging (in °C) from _______ to _______.

A) 20; 100
B) 20; 40
C) 0; 20
D) 0; 40
E) 0; 100

Question 31

Blood is a type of _______ tissue.

A) connective
B) epithelial
C) matrix
D) muscle
E) nervous

Question 32

The strength of skin and of the connections between bones is due to the protein

A) actin.
B) myosin.
C) elastin.
D) collagen.
E) reflexin.

Question 33

The Q₁₀, which describes the sensitivity of a reaction to temperature, is calculated as the

A) rate of a process at a certain temperature, divided by its rate at 10°C.
B) rate of a process at a certain temperature, divided by its rate at a temperature 10°C lower.
C) rate of a process at a certain temperature, divided by its rate at a temperature 10°C higher.
D) temperature at which the rate of a certain process doubles.
E) temperature at which the rate of a certain process becomes insignificant.

Question 34

Which of the following statements about tissues is false?

A) The protein elastin is found in tissues that are regularly stretched.
B) An organ is usually composed of a single type of tissue.
C) Epithelial tissue forms a boundary between the inside and outside of the body.
D) Adipose tissue is a form of connective tissue.
E) None of the above

Question 35

While working in a laboratory, you are shown a slide containing animal tissue composed of elongated cells and are told they represent the most abundant tissue type in the body. What is the function of this tissue?

A) Thermoregulation
B) Conducting nerve impulses
C) Generating forces and causing movement
D) Giving strength to the skin
E) Carrying oxygen throughout the body

Question 36

A Q₁₀ value of 3 indicates that a reaction rate has _______ over a temperature range of 10°C.

A) increased by 3 orders of magnitude
B) decreased by 3 orders of magnitude
C) tripled
D) decreased to one-third the normal rate
E) None of the above

Question 37

_______ are cells of the nervous system that do not conduct signals.

A) Hormones
B) Neurons
C) Glial cells
D) Ductless glands
E) Skeletal muscle cells

Question 38

Bone is a type of _______ tissue.

A) connective
B) epithelial
C) matrix
D) muscle
E) nervous

Question 39

Suppose that the rate of a particular biological function at 15°C is X. If the Q₁₀ of that function at 25°C is _______, the rate is _______.

A) 1; X
B) 1; 25
C) 2; X
D) 3; 2X
E) 3; 30

Question 40

Which of the following statements about muscle tissue is false?

A) It consists of cells that can contract.
B) It is the most abundant tissue in the body.
C) It is a form of connective tissue.
D) It uses a lot of energy when animals are active.
E) It includes skeletal, smooth, and cardiac muscle.

Question 41

Which of the following physiological control mechanisms is a response to a rise in body temperature?

A) Slower heart rate
B) Increased blood flow to the skin
C) Constriction of blood vessels in the skin
D) Contraction of muscles
E) Retention of water

Question 42

Which of the following animals is behaving as an endotherm to warm its body?

A) A moth that quivers its wings before flight
B) A black beetle that absorbs solar radiation
C) A snake that lies on a warm blacktop road
D) A fish that moves to a warm, shallow part of a pond
E) An insect that positions its body for maximum exposure to sunlight

Question 43

Compared to "cold" fish, "hot" fish, such as bluefin tuna, keep a higher temperature difference between their body and the surrounding water because they

A) produce thermogenins.
B) have a countercurrent heat exchange system of veins and arteries.
C) shiver to create more heat.
D) have many brown fat tissues.
E) have a large dorsal aorta that keeps them warm.

Question 44

Readjustment of an ectotherm's metabolic rate to compensate for seasonal thermal change is caused by the production of different

A) thermogenins.
B) pyrogens.
C) isozymes.
D) countercurrent exchangers.
E) None of the above

Question 45

As the environmental temperature in a closed, empty chamber increases (up to 25°C), the metabolic rate of an ectotherm _______ and that of an endotherm _______.

A) increases; increases
B) increases; decreases
C) decreases; increases
D) decreases; decreases
E) stays the same; decreases

Question 46

"Hot" fish pick up their heat

A) from brown fat.
B) by shivering.
C) by eating prey that live in warmer waters near the surface.
D) through metabolically active muscles.
E) by pressing against warm rocks in the intertidal zone.

Question 47

Endotherms invest energy to maintain their body tem­perature across most of the range of environmental temperatures they encounter, except in the range of environmental temperatures

A) that allow them to sweat.
B) compromise their thermoneutral zone.
C) above 45°C.
D) they encounter at night.
E) below 0°C.

Question 48

Organisms that sometimes regulate their own internal temperatures, but sometimes allow their temperature to be determined by the environment, are called

A) endotherms.
B) ectotherms.
C) heterotherms.
D) pyrotherms.
E) varitherms.

Question 49

Heat exchange between the internal environment and the skin occurs

A) only in endotherms through evaporation.
B) by means of pore openings.
C) only in ectotherms through respiration.
D) only in the thermoneutral zone.
E) in both ectotherms and endotherms through blood flow.

Question 50

A squirrel that metabolically maintains its internal temperature during the summer but hibernates during the winter is a(n)

A) endotherm.
B) ectotherm.
C) heterotherm.
D) pyrotherm.
E) varitherm.

Question 51

The elephant is better adapted to tropical habitats than to cold climates because of its

A) sparse hair.
B) large size.
C) stocky appendages.
D) vegetarian diet.
E) thick skin.

Question 52

Which of the following adaptations would not produce an increase in an ectotherm's body temperature?

A) Repeated contraction of flight muscles without movement
B) Cluster or huddling behavior
C) Decreased surface-to-surface contact with a cold environment
D) Circulatory changes to maintain core or internal temperatures greater than the animal's peripheral temperatures
E) Metabolism of brown fat

Question 53

Countercurrent heat exchange

A) moves warm blood coming from the muscles past cold blood flowing into the muscles.
B) allows "hot" fish to maintain body temperatures higher than the surrounding water temperature.
C) is found in large, rapidly swimming fish.
D) increases a fish's sustainable power output threefold for every 10°C rise in muscle temperature.
E) All of the above

Question 54

Organisms that depend largely on external sources of heat to maintain body temperature are called

A) homeothermic.
B) endothermic.
C) heterothermic.
D) ectothermic.
E) mesothermic.

Question 55

Which of the following terms is part of the thermal classification system for the range of strategies employed by animals?

A) Warm-blooded
B) Homeothermic
C) Cold-blooded
D) Poikilothermic
E) Endothermic

Question 56

In response to a 10°C rise in environmental temperature, an endotherm's body temperature will

A) rise at a constant rate.
B) fall at a constant rate.
C) fall to a point, then become stable.
D) rise to a point, then become stable.
E) remain relatively constant.

Question 57

Which of the following is not one of the thermoregulatory behaviors of a lizard (an ectotherm)?

A) Staying in a burrow when the surface temperature is below 10°C
B) Basking in the sun during early morning hours
C) Moving into the shade during midday hours
D) Pressing its cool body to the ground during the midday hours
E) Consuming prey that is ectothermic

Question 58

Which of the following animals are endotherms?

A) Fishes
B) Amphibians
C) Birds
D) Mammals
E) Both c and d

Question 59

Which of the following statements about heat exchange is false?

A) Conduction is the direct transfer of heat between two objects of different temperatures that have come into contact.
B) Evaporation of water from the surface of the body heats the body.
C) Ectotherms and endotherms can change the rate of heat exchange between their bodies and the external environment by changing blood flow to the skin.
D) Animals may lose heat by convection when they are exposed to wind with a temperature below that of their body surface.
E) None of the above

Question 60

Which of the following is an important adaptation of animals to cold climates?

A) Increased tendency to shiver
B) Thinner layers of body fat
C) Reduced density of fur or feathers
D) Reduced surface area-to-volume ratio
E) Increased flow of blood to surface

Question 61

The hypothalamus serves in part as an integrated thermoregulatory center defining an organism's response to changes in its thermal environment. Because the hypothalamus normally serves to produce metabolic responses that reverse the direction of environmental temperature change, the control it exerts is termed

A) positive feedback.
B) metabolic compensation.
C) negative feedback.
D) feedforward.
E) None of the above

Question 62

In a mammal, metabolic rate is highest when the temperature is _______ the thermoneutral zone and the animal is _______.

A) within; at rest
B) below; active
C) within; active
D) above; at rest
E) below; at rest

Question 63

Which of the following does not describe the limits of the thermoneutral zone in an endotherm?

A) The range of environmental temperatures between the upper critical and lower critical temperatures
B) The range of environmental temperatures over which an organism exhibits a basal metabolic rate
C) The range of body temperatures at which the metabolic rate is maximum
D) The range of environmental temperatures over which an organism's metabolic rate neither increases nor decreases for thermoregulation
E) All of the above describe the limits of the thermoneutral zone.

Question 64

Use the following to answer questions :
Predict the probable metabolic response of a mam­mal exposed to a 3°-5°C environmental temperature change from the list below.

-The environmental temperature fluctuates between the upper and the lower critical temperatures.

A) Increased metabolic rate
B) Decreased metabolic rate
C) No change in metabolic rate
D) Death

Question 65

Within a range of environmental temperatures called the thermoneutral zone, the metabolic rate of an endotherm is

A) variable.
B) low, and independent of temperature.
C) high, and independent of temperature.
D) below the basal metabolic rate.
E) dependent upon the temperature.

Question 66

Use the following to answer questions :
Predict the probable metabolic response of a mam­mal exposed to a 3°-5°C environmental temperature change from the list below.

-The environmental temperature begins at the upper critical temperature and increases above that point.

A) Increased metabolic rate
B) Decreased metabolic rate
C) No change in metabolic rate
D) Death

Question 67

Which of the following is the thermoregulatory response of the hypothalamus to a rise in temperature?

A) Increased metabolic heat production
B) Resetting of the thermostat to a higher setting
C) Dilation of blood vessels in the skin
D) Overall increase in body temperature
E) Initiation of shivering movements

Question 68

Anatomical features used by endotherms to reduce heat loss include

A) rounder body shapes.
B) shorter appendages.
C) increased thermal insulation.
D) Both b and c
E) All of the above

Question 69

Which of the following statements about thermoregulation is false?

A) Thermoregulatory set points are highest during sleep.
B) Entrance into hibernation begins with a decrease in metabolic rate.
C) Aspirin can lower the hypothalamic set point of a person with a fever.
D) Hypothermia may result from starvation.
E) All of the above

Question 70

Which of the following statements about brown fat is false?

A) It contains abundant mitochondria.
B) It provides the most energy for shivering.
C) It allows metabolic fuels to be consumed without producing ATP.
D) It uses thermogenin to uncouple proton movement from ATP production.
E) It is more abundant in hibernating animals.

Question 71

Use the following to answer questions :
Predict the probable metabolic response of a mam­mal exposed to a 3°-5°C environmental temperature change from the list below.

-The environmental temperature decreases far below 0°C.

A) Increased metabolic rate
B) Decreased metabolic rate
C) No change in metabolic rate
D) Death

Question 72

Which of the following statements about the thermoregulatory set point is true?

A) The set point for shivering is the same as the set point for panting.
B) In a given individual, the set points for all thermoregulatory processes are the same.
C) The set points for thermoregulatory processes are the same for all members of the same species.
D) Changes in skin temperature can change the metabolic set point.
E) The temperature of the hypothalamus serves as a positive feedback signal.

Question 73

Use the following to answer questions :
Predict the probable metabolic response of a mam­mal exposed to a 3°-5°C environmental temperature change from the list below.

-The environmental temperature begins at the lower critical temperature and increases above that point.

A) Increased metabolic rate
B) Decreased metabolic rate
C) No change in metabolic rate
D) Death

Question 74

Use the following to answer questions :
Predict the probable metabolic response of a mam­mal exposed to a 3°-5°C environmental temperature change from the list below.

-The environmental temperature begins at the lower critical temperature and decreases below that point.

A) Increased metabolic rate
B) Decreased metabolic rate
C) No change in metabolic rate
D) Death

Question 75

Use the following to answer questions :
Predict the probable metabolic response of a mam­mal exposed to a 3°-5°C environmental temperature change from the list below.

-The environmental temperature begins at 0°C and increases above that point.

A) Increased metabolic rate
B) Decreased metabolic rate
C) No change in metabolic rate
D) Death

Question 76

Increased heat for thermoregulation or thermogenesis is produced either by shivering or by nonshivering mechanisms. Which of the following is not necessary for nonshivering thermogenesis?

A) Brown fat
B) Thermogenin
C) Pyrogens
D) The consumption of metabolic fuels
E) The uncoupling of proton movement from ATP production

Question 77

The mechanism of heat production in brown fat depends on

A) inefficient use of ATP in metabolism.
B) rapid breakdown of protein.
C) rapid breakdown of fatty acids.
D) the shivering of skeletal muscles.
E) uncoupling proton movement from ATP production.

Question 78

Evaporative cooling is used only as a last resort by animals in hot and dry environments because

A) it is ineffective at dissipating heat.
B) not all of the water released by sweating or panting dissipates heat.
C) sweating requires energy expenditure.
D) it requires an insulating layer in the skin.
E) it requires a resetting of the animal's thermostat.

Question 79

Use the following to answer questions :
Predict the probable metabolic response of a mam­mal exposed to a 3°-5°C environmental temperature change from the list below.

-The environmental temperature begins at the upper critical temperature and decreases below that point.

A) Increased metabolic rate
B) Decreased metabolic rate
C) No change in metabolic rate
D) Death

Question 80

The vertebrate thermoregulatory center ("thermostat") is located within the central nervous system in the

A) pons.
B) cerebellum.
C) hypophysis.
D) medulla.
E) hypothalamus.