Question 1

Each molecule of hemoglobin can carry a maximum of _______ molecules of _______.

Accepted Answer

A)  four; O2 
B)  four; CO2 
C)  two; O2 
D)  six; O2 
E)  six; CO2 
A)  four; O2 
B)  four; CO2 
C)  two; O2 
D)  six; O2 
E)  six; CO2 A

Question 2

In fish gas exchange systems, blood flows through gill lamellae in a direction opposite to water flow, a phenomenon known as _______.

Accepted Answer

countercurrent exchange

Question 3

External _______ are highly branched folds of the body surface that are involved in gas exchange.

Accepted Answer

gills

Question 4

Which of the following characterizes the lungs of mammals?

Accepted Answer

A)  Air sacs 
B)  Tidal ventilation 
C)  Complete emptying in exhalation 
D)  Crosscurrent air flow 
E)  Countercurrent air flow 
A)  Air sacs 
B)  Tidal ventilation 
C)  Complete emptying in exhalation 
D)  Crosscurrent air flow 
E)  Countercurrent air flow

Question 5

When elephants are swimming, what protects the blood vessels around their lungs from water pressure damage?

Accepted Answer

A)  They swim only in shallow water. 
B)  Their lungs are attached to the chest cavity with dense connective tissue. 
C)  They hold their breath. 
D)  They have thick-walled blood vessels near their lungs. 
E)  Their ribs, which surround all their blood vessels, provide protection and support. 
A)  They swim only in shallow water. 
B)  Their lungs are attached to the chest cavity with dense connective tissue. 
C)  They hold their breath. 
D)  They have thick-walled blood vessels near their lungs. 
E)  Their ribs, which surround all their blood vessels, provide protection and support.

Question 6

Gas exchange in animals always involves

Accepted Answer

A)  cellular respiration. 
B)  breathing movements. 
C)  neural control. 
D)  diffusion between internal body fluids and the outside medium. 
E)  active transport of gases. 
A)  cellular respiration. 
B)  breathing movements. 
C)  neural control. 
D)  diffusion between internal body fluids and the outside medium. 
E)  active transport of gases.

Question 7

The largest proportion of CO2 carried by the blood is in the form of

Accepted Answer

A)  bicarbonate ions (HCO3-) carried in the plasma. 
B)  molecular CO2 dissolved in the plasma. 
C)  bicarbonate ions (HCO3-) carried within the red blood cells. 
D)  molecular CO2 chemically bound to hemoglobin. 
E)  molecular CO2 chemically bound to myoglobin. 
A)  bicarbonate ions (HCO3-) carried in the plasma. 
B)  molecular CO2 dissolved in the plasma. 
C)  bicarbonate ions (HCO3-) carried within the red blood cells. 
D)  molecular CO2 chemically bound to hemoglobin. 
E)  molecular CO2 chemically bound to myoglobin.

Question 8

The hemoglobin of a human fetus

Accepted Answer

A)  is the same as that of an adult. 
B)  has a higher affinity for O2 than adult hemoglobin has. 
C)  has only two protein subunits instead of four. 
D)  is supplied by the mother's red blood cells. 
E)  has a higher affinity for BPG than adult hemoglobin has. 
A)  is the same as that of an adult. 
B)  has a higher affinity for O2 than adult hemoglobin has. 
C)  has only two protein subunits instead of four. 
D)  is supplied by the mother's red blood cells. 
E)  has a higher affinity for BPG than adult hemoglobin has.

Question 9

The carotid and aortic bodies

Accepted Answer

A)  are blood vessels. 
B)  respond to significant declines in PO2. 
C)  increase respiration when blood volumes drop. 
D)  are electrosensors. 
E)  Both b and c 
A)  are blood vessels. 
B)  respond to significant declines in PO2. 
C)  increase respiration when blood volumes drop. 
D)  are electrosensors. 
E)  Both b and c

Question 10

Which of the following structures is the site of gas exchange in the lungs?

Accepted Answer

A)  Alveoli 
B)  Bronchi 
C)  Bronchioles 
D)  Trachea 
E)  Both a and b 
A)  Alveoli 
B)  Bronchi 
C)  Bronchioles 
D)  Trachea 
E)  Both a and b

Question 11

The gills of fish employ a countercurrent exchange mechanism to ensure that O2 is efficiently extracted from the water. Describe how the countercurrent exchange works.

Accepted Answer

In the countercurrent exchange in the gi

Question 12

The lower side of the thoracic cavity is formed by the

Accepted Answer

A)  diaphragm. 
B)  esophagus. 
C)  stomach. 
D)  ribs. 
E)  intercostal muscles. 
A)  diaphragm. 
B)  esophagus. 
C)  stomach. 
D)  ribs. 
E)  intercostal muscles.

Question 13

A small amount of CO2 in the bloodstream stimulates a _______ increase (large or small) in breathing rate.

Accepted Answer

Question 14

Bird and fish respiratory systems are similar in that both

Accepted Answer

A)  employ a countercurrent exchanger. 
B)  have air sacs. 
C)  function by means of unidirectional flow of the environmental medium over the gas exchange membranes. 
D)  consist of infoldings of the body. 
E)  All of the above 
A)  employ a countercurrent exchanger. 
B)  have air sacs. 
C)  function by means of unidirectional flow of the environmental medium over the gas exchange membranes. 
D)  consist of infoldings of the body. 
E)  All of the above

Question 15

In studies of dogs running on treadmills, C. R. Bainton found that when he doubled the speed of the treadmill,

Accepted Answer

A)  arterial CO2 levels increased exponentially by a power of 2. 
B)  arterial CO2 levels were unchanged. 
C)  respiratory rate was unchanged. 
D)  respiratory rate increased. 
E)  Both b and d 
A)  arterial CO2 levels increased exponentially by a power of 2. 
B)  arterial CO2 levels were unchanged. 
C)  respiratory rate was unchanged. 
D)  respiratory rate increased. 
E)  Both b and d

Question 16

If a planet were discovered where the barometric pressure was 2,000 mm Hg and the air was 15 percent O2, the partial pressure of its O2 at sea level would be

Accepted Answer

A)  15 percent. 
B)  15 mm Hg. 
C)  133 mm Hg. 
D)  300 mm Hg. 
E)  30 percent. 
A)  15 percent. 
B)  15 mm Hg. 
C)  133 mm Hg. 
D)  300 mm Hg. 
E)  30 percent.

Question 17

One effect of cigarette smoking on the lungs is

Accepted Answer

A)  the removal of mucus from the airways. 
B)  the immobilization of cilia lining the airways. 
C)  the speeding of airflow through the airways. 
D)  increased surfactant action. 
E)  increased surface area in alveoli. 
A)  the removal of mucus from the airways. 
B)  the immobilization of cilia lining the airways. 
C)  the speeding of airflow through the airways. 
D)  increased surfactant action. 
E)  increased surface area in alveoli.

Question 18

Breathing in vertebrates other than birds is _______ and is therefore less efficient than gas exchange in fish or birds.

Accepted Answer

A)  unidirectional 
B)  by diffusion 
C)  tidal 
D)  laminar 
E)  countercurrent 
A)  unidirectional 
B)  by diffusion 
C)  tidal 
D)  laminar 
E)  countercurrent

Question 19

The ability of hemoglobin to pick up or release O2 depends on

Accepted Answer

A)  the amount of blood in an organism. 
B)  the PO2 of its environment. 
C)  the PCO2 of its environment. 
D)  Both a and b 
E)  All of the above 
A)  the amount of blood in an organism. 
B)  the PO2 of its environment. 
C)  the PCO2 of its environment. 
D)  Both a and b 
E)  All of the above

Question 20

Oxygen can be exchanged more easily in air than in water because

Accepted Answer

A)  the oxygen content of air is higher than that of water. 
B)  oxygen diffuses more slowly in water than in air. 
C)  more energy is required to move water than air because water is denser. 
D)  Both a and b 
E)  All of the above 
A)  the oxygen content of air is higher than that of water. 
B)  oxygen diffuses more slowly in water than in air. 
C)  more energy is required to move water than air because water is denser. 
D)  Both a and b 
E)  All of the above

Exam 49: Gas Exchange in Animals

Each molecule of hemoglobin can carry a maximum of _______ molecules of _______.

In fish gas exchange systems, blood flows through gill lamellae in a direction opposite to water flow, a phenomenon known as _______.

External _______ are highly branched folds of the body surface that are involved in gas exchange.

Which of the following characterizes the lungs of mammals?

When elephants are swimming, what protects the blood vessels around their lungs from water pressure damage?

Gas exchange in animals always involves

The largest proportion of CO2 carried by the blood is in the form of

The hemoglobin of a human fetus

The carotid and aortic bodies

Which of the following structures is the site of gas exchange in the lungs?

The gills of fish employ a countercurrent exchange mechanism to ensure that O2 is efficiently extracted from the water. Describe how the countercurrent exchange works.

The lower side of the thoracic cavity is formed by the

A small amount of CO2 in the bloodstream stimulates a _______ increase (large or small) in breathing rate.

Bird and fish respiratory systems are similar in that both

In studies of dogs running on treadmills, C. R. Bainton found that when he doubled the speed of the treadmill,

If a planet were discovered where the barometric pressure was 2,000 mm Hg and the air was 15 percent O2, the partial pressure of its O2 at sea level would be

One effect of cigarette smoking on the lungs is

Breathing in vertebrates other than birds is _______ and is therefore less efficient than gas exchange in fish or birds.

The ability of hemoglobin to pick up or release O2 depends on

Oxygen can be exchanged more easily in air than in water because

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Filters

Each molecule of hemoglobin can carry a maximum of _ molecules of _.

The largest proportion of CO₂ carried by the blood is in the form of

The gills of fish employ a countercurrent exchange mechanism to ensure that O₂ is efficiently extracted from the water. Describe how the countercurrent exchange works.

A small amount of CO₂ in the bloodstream stimulates a _______ increase (large or small) in breathing rate.

If a planet were discovered where the barometric pressure was 2,000 mm Hg and the air was 15 percent O₂, the partial pressure of its O₂ at sea level would be

The ability of hemoglobin to pick up or release O₂ depends on