Question 1

Small insects may take a bubble of air underwater when they dive. The bubble can serve as an air tank for some time because

Accepted Answer

A)  as CO2 increases, the bubble inflates. 
B)  as O2 is consumed, air pressure in the bubble decreases. 
C)  as O2 is consumed, more O2 diffuses into the bubble. 
D)  the partial pressure of nitrogen remains constant. 
E)  for each O2 molecule used, a CO2 molecule replaces it. 
A)  as CO2 increases, the bubble inflates. 
B)  as O2 is consumed, air pressure in the bubble decreases. 
C)  as O2 is consumed, more O2 diffuses into the bubble. 
D)  the partial pressure of nitrogen remains constant. 
E)  for each O2 molecule used, a CO2 molecule replaces it.

Question 2

Breathing rhythm is generated in the _______ and is influenced by variation in levels of _______ in the blood.

Accepted Answer

A)  medulla; CO2 and O2 
B)  medulla; CO2 only 
C)  medulla; O2 only 
D)  frontal lobe; CO2 and O2 
E)  frontal lobe; CO2 only 
A)  medulla; CO2 and O2 
B)  medulla; CO2 only 
C)  medulla; O2 only 
D)  frontal lobe; CO2 and O2 
E)  frontal lobe; CO2 only

Question 3

In birds, after a second full breath, air leaves the _______ and passes through the _______ air sacs.

Accepted Answer

A)  lungs; posterior 
B)  alveoli; anterior 
C)  alveoli; posterior 
D)  lungs; anterior 
E)  alveoli; tracheal 
A)  lungs; posterior 
B)  alveoli; anterior 
C)  alveoli; posterior 
D)  lungs; anterior 
E)  alveoli; tracheal

Question 4

A _______ is a device that measures the volume of air breathed in and out.

Accepted Answer

A)  stethoscope 
B)  thermometer 
C)  cryostat 
D)  respirator 
E)  spirometer 
A)  stethoscope 
B)  thermometer 
C)  cryostat 
D)  respirator 
E)  spirometer

Question 5

Rapid gas exchange can be accomplished more easily in air than in water because

Accepted Answer

A)  the O2 content of water is higher than that of air. 
B)  the CO2 content of water is higher than that of air. 
C)  O2 diffuses more rapidly in water than in air. 
D)  water is more dense and viscous than air. 
E)  more energy is required to move air than to move water. 
A)  the O2 content of water is higher than that of air. 
B)  the CO2 content of water is higher than that of air. 
C)  O2 diffuses more rapidly in water than in air. 
D)  water is more dense and viscous than air. 
E)  more energy is required to move air than to move water.

Question 6

Why is air a better respiratory medium than water?

Accepted Answer

A)  A given volume of air can contain more O2 than the same volume of water. 
B)  O2 diffuses faster in air than in water. 
C)  Less work is required to move air over respiratory exchange surfaces. 
D)  Both a and c 
E)  All of the above 
A)  A given volume of air can contain more O2 than the same volume of water. 
B)  O2 diffuses faster in air than in water. 
C)  Less work is required to move air over respiratory exchange surfaces. 
D)  Both a and c 
E)  All of the above

Question 7

Which of the following statements about surfactants in the lungs is false?

Accepted Answer

A)  Water coating the respiratory surfaces of the lungs creates surface tension. 
B)  Surfactants increase the cohesive forces between water molecules. 
C)  Certain cells in the alveoli produce surfactants. 
D)  Surface tension influences the amount of effort required to inflate the lungs. 
E)  Premature infants suffer respiratory distress syndrome if natural surfactants are not present within the lungs. 
A)  Water coating the respiratory surfaces of the lungs creates surface tension. 
B)  Surfactants increase the cohesive forces between water molecules. 
C)  Certain cells in the alveoli produce surfactants. 
D)  Surface tension influences the amount of effort required to inflate the lungs. 
E)  Premature infants suffer respiratory distress syndrome if natural surfactants are not present within the lungs.

Question 8

Which of the following statements about O2-binding curves is false?

Accepted Answer

A)  A smaller decrease in PO2 is needed for hemoglobin to drop from 100 percent to 75 percent saturation than for hemoglobin to drop from 75 percent to 50 percent saturation. 
B)  In normal metabolism, the body uses only the upper one-fourth of its oxygen-binding curve. 
C)  The blood normally carries an enormous reserve of O2. 
D)  The steepest part of the O2-binding curve results in a great release of O2 for only a modest drop in PO2. 
E)  The PO2 of blood drops below about 40 mm Hg only during extreme exertion. 
A)  A smaller decrease in PO2 is needed for hemoglobin to drop from 100 percent to 75 percent saturation than for hemoglobin to drop from 75 percent to 50 percent saturation. 
B)  In normal metabolism, the body uses only the upper one-fourth of its oxygen-binding curve. 
C)  The blood normally carries an enormous reserve of O2. 
D)  The steepest part of the O2-binding curve results in a great release of O2 for only a modest drop in PO2. 
E)  The PO2 of blood drops below about 40 mm Hg only during extreme exertion.

Question 9

The amount of O2 carried by hemoglobin depends on the PO2 in the blood. Hemoglobin in active muscles

Accepted Answer

A)  becomes saturated with O2. 
B)  takes up only a small amount of O2. 
C)  readily unloads O2. 
D)  tends to decrease the PO2 in the muscle tissues. 
E)  is denatured. 
A)  becomes saturated with O2. 
B)  takes up only a small amount of O2. 
C)  readily unloads O2. 
D)  tends to decrease the PO2 in the muscle tissues. 
E)  is denatured.

Question 10

How can an aquatic animal with no specialized respiratory surfaces get enough O2 to all of its cells to survive?

Accepted Answer

Since it has no respiratory surfaces, an

Question 11

Breathing provides the body with the oxygen required to support the energy metabolism of all cells and also eliminates _______, one of the waste products of cell metabolism.

Accepted Answer

A)  carbon dioxide 
B)  carbon monoxide 
C)  carbon tetrachloride 
D)  calcium carbonate 
E)  carbonic acid 
A)  carbon dioxide 
B)  carbon monoxide 
C)  carbon tetrachloride 
D)  calcium carbonate 
E)  carbonic acid

Question 12

Most of the CO2 in the blood is transported as _______, and it is located mainly in the _______.

Accepted Answer

A)  CO2; plasma 
B)  H2CO3; plasma 
C)  HCO3-; plasma 
D)  carboxyhemoglobin; erythrocytes 
E)  HCO3-; erythrocytes 
A)  CO2; plasma 
B)  H2CO3; plasma 
C)  HCO3-; plasma 
D)  carboxyhemoglobin; erythrocytes 
E)  HCO3-; erythrocytes

Question 13

In which of the following PO2 environments would hemoglobin release its O2 most easily?

Accepted Answer

A)  30 mm Hg 
B)  50 mm Hg 
C)  70 mm Hg 
D)  90 mm Hg 
E)  110 mm Hg 
A)  30 mm Hg 
B)  50 mm Hg 
C)  70 mm Hg 
D)  90 mm Hg 
E)  110 mm Hg

Question 14

Why are elephants better "snorkelers" than humans, in deep water?

Accepted Answer

A)  Humans possess dense connective tissue that is attached to the surface of the lungs to the surface of the chest cavity, resulting in fragile blood vessels at the surface of the lungs. 
B)  Elephants possess dense connective tissue that is attached to the surface of the lungs to the surface of the chest cavity, strengthening the blood vessels at the surface of the lungs. 
C)  Elephants can hold their breath longer than humans under water. 
D)  Elephants have a larger lung capacity than humans. 
E)  None of the above 
A)  Humans possess dense connective tissue that is attached to the surface of the lungs to the surface of the chest cavity, resulting in fragile blood vessels at the surface of the lungs. 
B)  Elephants possess dense connective tissue that is attached to the surface of the lungs to the surface of the chest cavity, strengthening the blood vessels at the surface of the lungs. 
C)  Elephants can hold their breath longer than humans under water. 
D)  Elephants have a larger lung capacity than humans. 
E)  None of the above

Question 15

Nodes that are sensitive to O2 and blood pressure levels are located in the

Accepted Answer

A)  aorta and carotid arteries. 
B)  brain stem capillaries. 
C)  hypothalamus. 
D)  pulmonary artery. 
E)  pulmonary vein. 
A)  aorta and carotid arteries. 
B)  brain stem capillaries. 
C)  hypothalamus. 
D)  pulmonary artery. 
E)  pulmonary vein.

Question 16

Aquatic _______ are in a double bind, because their demand for oxygen increases as the temperature of their environment increases, but the oxygen content of water declines with increasing water temperatures.

Accepted Answer

A)  insects 
B)  ectotherms 
C)  endotherms 
D)  plants 
E)  None of the above 
A)  insects 
B)  ectotherms 
C)  endotherms 
D)  plants 
E)  None of the above

Question 17

The shape of the oxygen dissociation curve of hemoglobin is _______.

Accepted Answer

sigmoidal

Question 18

Why would a tropical fish in a fish tank face severe respiratory problems (and possibly death) if the heater in the tank malfunctioned and caused extremely high water temperatures?

Accepted Answer

The tropical fish would be facing the do

Question 19

The presence of CO2 in blood will lower pH because CO2 combines with _______, with the rate of reaction increased by _______.

Accepted Answer

A)  H2O to form H+ and HCO3-; carbonic anhydrase 
B)  H2O to form only HCO3-; carbonic anhydrase 
C)  H2O to form only H+; carbonic ions 
D)  H+ to form HCO3-; oxyhemoglobin 
E)  H2O to form H+ and HCO3-; fetal hemoglobin 
A)  H2O to form H+ and HCO3-; carbonic anhydrase 
B)  H2O to form only HCO3-; carbonic anhydrase 
C)  H2O to form only H+; carbonic ions 
D)  H+ to form HCO3-; oxyhemoglobin 
E)  H2O to form H+ and HCO3-; fetal hemoglobin

Question 20

Neural control of breathing is a function of the

Accepted Answer

A)  cerebrum. 
B)  diaphragm. 
C)  medulla. 
D)  olfactory lobe. 
E)  spinal cord. 
A)  cerebrum. 
B)  diaphragm. 
C)  medulla. 
D)  olfactory lobe. 
E)  spinal cord.

Exam 49: Gas Exchange in Animals

Small insects may take a bubble of air underwater when they dive. The bubble can serve as an air tank for some time because

Breathing rhythm is generated in the _______ and is influenced by variation in levels of _______ in the blood.

In birds, after a second full breath, air leaves the _______ and passes through the _______ air sacs.

A _______ is a device that measures the volume of air breathed in and out.

Rapid gas exchange can be accomplished more easily in air than in water because

Why is air a better respiratory medium than water?

Which of the following statements about surfactants in the lungs is false?

Which of the following statements about O2-binding curves is false?

The amount of O2 carried by hemoglobin depends on the PO2 in the blood. Hemoglobin in active muscles

How can an aquatic animal with no specialized respiratory surfaces get enough O2 to all of its cells to survive?

Breathing provides the body with the oxygen required to support the energy metabolism of all cells and also eliminates _______, one of the waste products of cell metabolism.

Most of the CO2 in the blood is transported as _______, and it is located mainly in the _______.

In which of the following PO2 environments would hemoglobin release its O2 most easily?

Why are elephants better "snorkelers" than humans, in deep water?

Nodes that are sensitive to O2 and blood pressure levels are located in the

Aquatic _______ are in a double bind, because their demand for oxygen increases as the temperature of their environment increases, but the oxygen content of water declines with increasing water temperatures.

The shape of the oxygen dissociation curve of hemoglobin is _______.

Why would a tropical fish in a fish tank face severe respiratory problems (and possibly death) if the heater in the tank malfunctioned and caused extremely high water temperatures?

The presence of CO2 in blood will lower pH because CO2 combines with _______, with the rate of reaction increased by _______.

Neural control of breathing is a function of the

Studying Life

Small Molecules and the Chemistry of Life

Proteins, Carbohydrates, and Lipids

Nucleic Acids and the Origin of Life

Cells: the Working Units of Life

Cell Membranes

Cell Signaling and Communication

Energy, Enzymes, and Metabolism

Pathways That Harvest Chemical Energy

Photosynthesis: Energy From Sunlight

The Cell Cycle and Cell Division

Inheritance, Genes, and Chromosomes

Dna and Its Role in Heredity

From Dna to Protein: Gene Expression

Gene Mutation and Molecular Medicine

Regulation of Gene Expression

Genomes

Recombinent Dna and Biotechnology

Differential Gene Expression in Development

Development and Evolutionary Change

Evidence and Mechanisms of Evolution

Reconstructing and Using Phylogenies

Species and Their Formation

Evolution of Genes and Genomes

The History of Life on Earth

Bacteria and Archaea: the Prokaryotic Domains

The Origin and Diversification of Eukaryotes

Plants Without Seeds: From Water to Land

The Evolution of Seed Plants

Fungi: Recyclers, Pathogens, Parasites, and Plant Partners

Animal Origins and the Evolution of Body Plans

Protostome Animals

Deuterostome Animals

The Plant Body

Transport in Plants

Plant Nutrition

Regulation of Plant Growth

Reproduction in Flowering Plants

Plant Responses to Environmental Challenges

Physiology, Homeostasis, and Temperature Regulation

Animal Hormones

Immunology: Animal Defense Systems

Animal Reproduction

Animal Development

Neurons and Nervous Systems

Sensory Systems

The Mammalian Nervous System: Structure and Higher Function

Musculoskeletal Systems

Circulatory Systems

Nutrition, Digestion, and Absorption

Salt and Water Balance and Nitrogen

Animal Behavior

Ecology and the Distribution of Life

Population Ecology

Species Interaction and Coevolution

Community Ecology

Ecosystems and Global Ecology

Conservation Biology

Filters

Breathing rhythm is generated in the _ and is influenced by variation in levels of _ in the blood.

In birds, after a second full breath, air leaves the _ and passes through the _ air sacs.

Which of the following statements about O₂-binding curves is false?

The amount of O₂ carried by hemoglobin depends on the P_O2 in the blood. Hemoglobin in active muscles

How can an aquatic animal with no specialized respiratory surfaces get enough O₂ to all of its cells to survive?

Most of the CO₂ in the blood is transported as _, and it is located mainly in the _.

In which of the following P_O2 environments would hemoglobin release its O₂ most easily?

Nodes that are sensitive to O₂ and blood pressure levels are located in the

The presence of CO₂ in blood will lower pH because CO₂ combines with _, with the rate of reaction increased by _.