Question 1

In Fick's law of diffusion, the term (P1 - P2)/L refers to the _______ gradient.

Accepted Answer

Question 2

Which of the following statements about the structure of the fish gill is false?

Accepted Answer

A)  Afferent vessels bring blood to the gills, whereas efferent vessels take blood away from the gills. 
B)  Exchange of respiratory gases occurs within the lamellae of the gill filaments. 
C)  The efferent and afferent vessels are the counter-current flow system of the gill. 
D)  The lamellae greatly increase the surface area for gas exchange. 
E)  The opercular flaps enclose the gill chambers. 
A)  Afferent vessels bring blood to the gills, whereas efferent vessels take blood away from the gills. 
B)  Exchange of respiratory gases occurs within the lamellae of the gill filaments. 
C)  The efferent and afferent vessels are the counter-current flow system of the gill. 
D)  The lamellae greatly increase the surface area for gas exchange. 
E)  The opercular flaps enclose the gill chambers.

Question 3

There are no active transport mechanisms for respiratory gases. Therefore, the only means by which respiratory gases are exchanged is _______.

Accepted Answer

The answer of There are no active transport mechanisms for...

Question 4

Which of the following would increase the amount of oxygen diffusing from the lungs into the blood?

Accepted Answer

A)  An increase in the binding rate of O2 to hemoglobin 
B)  A decrease in the partial pressure of O2 in the lungs 
C)  An increase in the partial pressure of O2 in the blood 
D)  A decrease in the red blood cell count 
E)  An increase in the water vapor of air in the lungs 
A)  An increase in the binding rate of O2 to hemoglobin 
B)  A decrease in the partial pressure of O2 in the lungs 
C)  An increase in the partial pressure of O2 in the blood 
D)  A decrease in the red blood cell count 
E)  An increase in the water vapor of air in the lungs

Question 5

Which of the following statements about the binding of oxygen by hemoglobin is false?

Accepted Answer

A)  The percentage of completely O2-saturated hemoglobin increases as PO2 increases. 
B)  The oxygen-binding curve is S-shaped. 
C)  There is a narrow range of the O2-binding curve where O2 dissociation-association is rapid. 
D)  A very low PO2 is required for all four hemoglobin subunits to bind to O2. 
E)  If one subunit of a completely oxygen-saturated hemoglobin loses its O2, the affinity of the remaining subunits for their O2 increases. 
A)  The percentage of completely O2-saturated hemoglobin increases as PO2 increases. 
B)  The oxygen-binding curve is S-shaped. 
C)  There is a narrow range of the O2-binding curve where O2 dissociation-association is rapid. 
D)  A very low PO2 is required for all four hemoglobin subunits to bind to O2. 
E)  If one subunit of a completely oxygen-saturated hemoglobin loses its O2, the affinity of the remaining subunits for their O2 increases.

Question 6

Air flows into the lungs of mammals during inhalation because the

Accepted Answer

A)  pressure in the lungs falls below atmospheric pressure. 
B)  volume of the lungs decreases. 
C)  pressure in the lungs rises above atmospheric pressure. 
D)  diaphragm moves upward toward the lungs. 
E)  internal intercostal muscles contract. 
A)  pressure in the lungs falls below atmospheric pressure. 
B)  volume of the lungs decreases. 
C)  pressure in the lungs rises above atmospheric pressure. 
D)  diaphragm moves upward toward the lungs. 
E)  internal intercostal muscles contract.

Question 7

Refer to the graph below. Curve _______ would most likely belong to a fetus, curve _______ would most likely belong to an adult human with blood at pH 7.2, and curve _______ would most likely belong to a human with blood at pH 7.4.

Accepted Answer

A)  A; B; C 
B)  A; C; B 
C)  B; A; C 
D)  B; C; A 
E)  C; B; A 
A)  A; B; C 
B)  A; C; B 
C)  B; A; C 
D)  B; C; A 
E)  C; B; A

Question 8

The movement of O2 and CO2 between the blood in the tissue capillaries and the cells in tissues depends most directly upon

Accepted Answer

A)  active transport of O2 and CO2. 
B)  total atmospheric (barometric) pressure differences across the cell membranes. 
C)  diffusion of O2 and CO2 down a concentration gradient. 
D)  diffusion of O2 and CO2 down a partial pressure gradient. 
E)  osmosis across cell membranes. 
A)  active transport of O2 and CO2. 
B)  total atmospheric (barometric) pressure differences across the cell membranes. 
C)  diffusion of O2 and CO2 down a concentration gradient. 
D)  diffusion of O2 and CO2 down a partial pressure gradient. 
E)  osmosis across cell membranes.

Question 9

If the O2-binding curves were plotted for the following molecules, which curve would be to the left of all the others?

Accepted Answer

A)  Fetal human hemoglobin 
B)  Adult llama hemoglobin 
C)  Adult human hemoglobin 
D)  Myoglobin 
E)  Fetal llama hemoglobin 
A)  Fetal human hemoglobin 
B)  Adult llama hemoglobin 
C)  Adult human hemoglobin 
D)  Myoglobin 
E)  Fetal llama hemoglobin

Question 10

A large drop in arterial O2 has a (large or small) _______ effect on breathing rate.

Accepted Answer

Question 11

Which of the following statements about the mechanics of ventilation is false?

Accepted Answer

A)  If the pleural cavity is punctured, the lung may collapse. 
B)  As the diaphragm relaxes, air is expelled from the respiratory system. 
C)  As the diaphragm relaxes, pressure within the pleural cavities increases. 
D)  Less energy is expended during the exhalation phase than during the inhalation phase. 
E)  There is a slight positive pressure within the pleural cavities between breaths. 
A)  If the pleural cavity is punctured, the lung may collapse. 
B)  As the diaphragm relaxes, air is expelled from the respiratory system. 
C)  As the diaphragm relaxes, pressure within the pleural cavities increases. 
D)  Less energy is expended during the exhalation phase than during the inhalation phase. 
E)  There is a slight positive pressure within the pleural cavities between breaths.

Question 12

Respiratory gases are exchanged between the body fluids of an animal and its environment by

Accepted Answer

A)  osmosis. 
B)  active transport. 
C)  passive transport. 
D)  diffusion. 
E)  pinocytosis. 
A)  osmosis. 
B)  active transport. 
C)  passive transport. 
D)  diffusion. 
E)  pinocytosis.

Question 13

C. R. Bainton conducted an experiment in which he increased the workload of dogs by having them run on inclined treadmills and showed that respiratory rate responded to CO2 levels. However, this success story followed an earlier experiment that did not support his hypothesis. In the earlier study, he

Accepted Answer

A)  compared respiratory rate of dogs versus cats. 
B)  compared sleeping versus barking dogs. 
C)  changed the speed at which the dogs ran. 
D)  changed the dog's motivation by keeping them food-stressed. 
E)  injected dissolved O2 into the dogs' arteries. 
A)  compared respiratory rate of dogs versus cats. 
B)  compared sleeping versus barking dogs. 
C)  changed the speed at which the dogs ran. 
D)  changed the dog's motivation by keeping them food-stressed. 
E)  injected dissolved O2 into the dogs' arteries.

Question 14

Which of the following statements about the air sacs of birds is false?

Accepted Answer

A)  They connect with each other. 
B)  They occur in anterior and posterior pairs. 
C)  They make the bird's respiratory system more efficient than a mammal's. 
D)  They allow for one-way air flow through the lungs. 
E)  They provide an extra gas exchange surface. 
A)  They connect with each other. 
B)  They occur in anterior and posterior pairs. 
C)  They make the bird's respiratory system more efficient than a mammal's. 
D)  They allow for one-way air flow through the lungs. 
E)  They provide an extra gas exchange surface.

Question 15

Our sensors for detecting PO2 levels are found in blood vessels leaving the _______.

Accepted Answer

Question 16

Unlike humans and other mammals, fishes respond to _______ to adjust their respiratory rate.

Accepted Answer

A)  PCO2 
B)  PO2 
C)  PN2 
D)  PCO 
E)  turbidity 
A)  PCO2 
B)  PO2 
C)  PN2 
D)  PCO 
E)  turbidity

Question 17

At sea level, atmospheric pressure is about _______ mm mercury.

Accepted Answer

A)  454 
B)  1,000 
C)  760 
D)  940 
E)  1 
A)  454 
B)  1,000 
C)  760 
D)  940 
E)  1

Question 18

If the thoracic wall is punctured, air leaking in will cause the lung to collapse. Thus, in the normal, intact thoracic cavity,

Accepted Answer

A)  lung expansion is passive. 
B)  air pressure is the same as it is on the outside. 
C)  a slight suction keeps lungs inflated. 
D)  breathing movements keep lungs inflated. 
E)  Both a and b 
A)  lung expansion is passive. 
B)  air pressure is the same as it is on the outside. 
C)  a slight suction keeps lungs inflated. 
D)  breathing movements keep lungs inflated. 
E)  Both a and b

Question 19

The respiratory system of insects consists of

Accepted Answer

A)  branched air tubes called spiracles that supply capillaries. 
B)  branched air tubes called tracheae that supply capillaries. 
C)  branching gill systems that end in openings called tracheae. 
D)  branching gill systems that end in openings called spiracles. 
E)  extensive layers of gas exchange tissue just under the exoskeleton. 
A)  branched air tubes called spiracles that supply capillaries. 
B)  branched air tubes called tracheae that supply capillaries. 
C)  branching gill systems that end in openings called tracheae. 
D)  branching gill systems that end in openings called spiracles. 
E)  extensive layers of gas exchange tissue just under the exoskeleton.

Question 20

Myoglobin benefits muscle cells by

Accepted Answer

A)  binding with O2 just as easily as hemoglobin does. 
B)  contributing to the elasticity of flight muscle in birds. 
C)  increasing the effectiveness of muscles used in short bursts. 
D)  releasing bound O2 at lower PO2 conditions than hemoglobin does. 
E)  using hemoglobin as a reserve source of oxygen. 
A)  binding with O2 just as easily as hemoglobin does. 
B)  contributing to the elasticity of flight muscle in birds. 
C)  increasing the effectiveness of muscles used in short bursts. 
D)  releasing bound O2 at lower PO2 conditions than hemoglobin does. 
E)  using hemoglobin as a reserve source of oxygen.

Exam 49: Gas Exchange in Animals

In Fick's law of diffusion, the term (P1 - P2)/L refers to the _______ gradient.

Which of the following statements about the structure of the fish gill is false?

There are no active transport mechanisms for respiratory gases. Therefore, the only means by which respiratory gases are exchanged is _______.

Which of the following would increase the amount of oxygen diffusing from the lungs into the blood?

Which of the following statements about the binding of oxygen by hemoglobin is false?

Air flows into the lungs of mammals during inhalation because the

Refer to the graph below. Curve _______ would most likely belong to a fetus, curve _______ would most likely belong to an adult human with blood at pH 7.2, and curve _______ would most likely belong to a human with blood at pH 7.4.

The movement of O2 and CO2 between the blood in the tissue capillaries and the cells in tissues depends most directly upon

If the O2-binding curves were plotted for the following molecules, which curve would be to the left of all the others?

A large drop in arterial O2 has a (large or small) _______ effect on breathing rate.

Which of the following statements about the mechanics of ventilation is false?

Respiratory gases are exchanged between the body fluids of an animal and its environment by

Which of the following statements about the air sacs of birds is false?

Our sensors for detecting PO2 levels are found in blood vessels leaving the _______.

Unlike humans and other mammals, fishes respond to _______ to adjust their respiratory rate.

At sea level, atmospheric pressure is about _______ mm mercury.

If the thoracic wall is punctured, air leaking in will cause the lung to collapse. Thus, in the normal, intact thoracic cavity,

The respiratory system of insects consists of

Myoglobin benefits muscle cells by

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In Fick's law of diffusion, the term (P₁ - P₂)/L refers to the _______ gradient.

Refer to the graph below. Curve ___ would most likely belong to a fetus, curve _ would most likely belong to an adult human with blood at pH 7.2, and curve _____ would most likely belong to a human with blood at pH 7.4.

The movement of O₂ and CO₂ between the blood in the tissue capillaries and the cells in tissues depends most directly upon

If the O₂-binding curves were plotted for the following molecules, which curve would be to the left of all the others?

A large drop in arterial O₂ has a (large or small) _______ effect on breathing rate.

Our sensors for detecting P_O2 levels are found in blood vessels leaving the _______.