Question 1

During most daily activities, the human respiration rate is most closely linked to the blood levels of ________.

Accepted Answer

A)  nitrogen 
B)  oxygen 
C)  carbon dioxide 
D)  carbon monoxide 
A)  nitrogen 
B)  oxygen 
C)  carbon dioxide 
D)  carbon monoxide C

Question 2

During aerobic exercise, the partial pressure of oxygen in muscle cells will ________, thus the rate of diffusion of oxygen into the muscle tissue from the blood will ________.

Accepted Answer

A)  decrease; increase 
B)  increase; decrease 
C)  not change; also not change 
D)  decrease; decrease 
A)  decrease; increase 
B)  increase; decrease 
C)  not change; also not change 
D)  decrease; decrease A

Question 3

Compared with the interstitial fluid that bathes active muscle cells, blood reaching these cells in arterioles has a

Accepted Answer

A)  higher ᴾO₂. 
B)  higher ᴾCO₂. 
C)  greater bicarbonate concentration. 
D)  lower pH. 
A)  higher ᴾO₂. 
B)  higher ᴾCO₂. 
C)  greater bicarbonate concentration. 
D)  lower pH. A

Question 4

Which of the following mechanisms are used to regulate blood pressure in the closed circulatory system of vertebrates?
I.changing the force of heart contraction
II.constricting and relaxing smooth muscle in the walls of arterioles
III.opening or closing precapillary sphincters

Accepted Answer

A)  only I and II 
B)  only I and III 
C)  only II and III 
D)  I, II, and III 
A)  only I and II 
B)  only I and III 
C)  only II and III 
D)  I, II, and III

Question 5

Damage to the sinoatrial node in humans would ________.

Accepted Answer

A)  block conductance between the bundle branches and the Purkinje fibers 
B)  have a negative effect on peripheral resistance 
C)  disrupt the rate and timing of cardiac muscle contractions 
D)  have a direct effect on blood pressure monitors in the aorta 
A)  block conductance between the bundle branches and the Purkinje fibers 
B)  have a negative effect on peripheral resistance 
C)  disrupt the rate and timing of cardiac muscle contractions 
D)  have a direct effect on blood pressure monitors in the aorta

Question 6

How has the avian lung adapted to the metabolic demands of flight?

Accepted Answer

A)  Airflow through the avian lung is bidirectional like in mammals. 
B)  There is more dead space within the avian lung so that oxygen can be stored for future use. 
C)  Countercurrent circulation is present in the avian lung. 
D)  Gas exchange occurs during both inhalation and exhalation. 
A)  Airflow through the avian lung is bidirectional like in mammals. 
B)  There is more dead space within the avian lung so that oxygen can be stored for future use. 
C)  Countercurrent circulation is present in the avian lung. 
D)  Gas exchange occurs during both inhalation and exhalation.

Question 7

Which of the following develops the greatest pressure on the blood in the mammalian aorta?

Accepted Answer

A)  systole of the left atrium 
B)  diastole of the right ventricle 
C)  systole of the left ventricle 
D)  diastole of the right atrium 
A)  systole of the left atrium 
B)  diastole of the right ventricle 
C)  systole of the left ventricle 
D)  diastole of the right atrium

Question 8

An anthropologist discovers the fossilized heart of an extinct animal. The evidence indicates that the organism's heart was large, was well-formed, and had four chambers, with no connection between the right and left sides. A reasonable conclusion supported by these observations is that the ________.

Accepted Answer

A)  animal had evolved from birds 
B)  animal was endothermic and had a high metabolic rate 
C)  animal was most closely related to alligators and crocodiles 
D)  species had little to no need to regulate blood pressure 
A)  animal had evolved from birds 
B)  animal was endothermic and had a high metabolic rate 
C)  animal was most closely related to alligators and crocodiles 
D)  species had little to no need to regulate blood pressure

Question 9

The velocity of blood flow is the lowest in capillaries because ________.

Accepted Answer

A)  the capillaries have internal valves that slow the flow of blood 
B)  the diastolic blood pressure is too low to deliver blood to the capillaries at a high flow rate 
C)  the systemic capillaries are supplied by the left ventricle, which has a lower cardiac output than the right ventricle 
D)  the total cross-sectional area of the capillaries is greater than the total cross-sectional area of the arteries or any other part of the circulatory system 
A)  the capillaries have internal valves that slow the flow of blood 
B)  the diastolic blood pressure is too low to deliver blood to the capillaries at a high flow rate 
C)  the systemic capillaries are supplied by the left ventricle, which has a lower cardiac output than the right ventricle 
D)  the total cross-sectional area of the capillaries is greater than the total cross-sectional area of the arteries or any other part of the circulatory system

Question 10

Which of the following events would you predict as carbon dioxide is released from your muscles into the surrounding capillary bed?

Accepted Answer

A)  Oxygen delivery to muscle is increased when more carbon dioxide is produced by the muscle. 
B)  Because of the change in blood pH, the blood can carry more oxygen. 
C)  The amount of oxygen in venous blood will increase. 
D)  Arterial blood entering the capillaries will carry more oxygen. 
A)  Oxygen delivery to muscle is increased when more carbon dioxide is produced by the muscle. 
B)  Because of the change in blood pH, the blood can carry more oxygen. 
C)  The amount of oxygen in venous blood will increase. 
D)  Arterial blood entering the capillaries will carry more oxygen.

Question 11

Carbon dioxide levels in the blood and cerebrospinal fluid affect pH. This enables the organism to sense a disturbance in gas levels as ________.

Accepted Answer

A)  the brain directly measures and monitors oxygen levels and causes breathing changes accordingly 
B)  the medulla oblongata, which is in contact with cerebrospinal fluid, monitors pH and uses this measure to control breathing 
C)  the brain alters the pH of the cerebrospinal fluid to force the animal to retain more or less carbon dioxide 
D)  stretch receptors in the lungs cause the medulla oblongata to speed up or slow breathing 
A)  the brain directly measures and monitors oxygen levels and causes breathing changes accordingly 
B)  the medulla oblongata, which is in contact with cerebrospinal fluid, monitors pH and uses this measure to control breathing 
C)  the brain alters the pH of the cerebrospinal fluid to force the animal to retain more or less carbon dioxide 
D)  stretch receptors in the lungs cause the medulla oblongata to speed up or slow breathing

Question 12

Which of the following represents the correct flow of air into the lung of a mammal?

Accepted Answer

A)  trachea → bronchioles → bronchi → alveoli 
B)  larnyx → trachea → bronchi → bronchioles → alveoli 
C)  trachea → tracheoles → bronchi → alveoli 
D)  alveoli → tracheoles → bronchi → trachea 
A)  trachea → bronchioles → bronchi → alveoli 
B)  larnyx → trachea → bronchi → bronchioles → alveoli 
C)  trachea → tracheoles → bronchi → alveoli 
D)  alveoli → tracheoles → bronchi → trachea

Question 13

The greatest difference in the concentration of respiratory gases is found in which of the following pairs of mammalian blood vessels?

Accepted Answer

A)  the pulmonary vein and the superior vena cava 
B)  the veins from the right and left legs 
C)  the pulmonary artery and the inferior vena cava 
D)  the pulmonary vein and the aorta 
A)  the pulmonary vein and the superior vena cava 
B)  the veins from the right and left legs 
C)  the pulmonary artery and the inferior vena cava 
D)  the pulmonary vein and the aorta

Question 14

When the air in a testing chamber is specially mixed so that its oxygen content is 10% and its overall air pressure is 400 mm Hg, then PO₂ is ________.

Accepted Answer

A)  400 mm Hg 
B)  82 mm Hg 
C)  40 mm Hg 
D)  4 mm Hg 
A)  400 mm Hg 
B)  82 mm Hg 
C)  40 mm Hg 
D)  4 mm Hg

Question 15

Compared to mammals that are not adapted for diving, diving mammals ________.

Accepted Answer

A)  have larger lungs 
B)  can store more oxygen in their muscles 
C)  use gills for gas exchange 
D)  always keep blood flowing to their lungs during a dive 
A)  have larger lungs 
B)  can store more oxygen in their muscles 
C)  use gills for gas exchange 
D)  always keep blood flowing to their lungs during a dive

Question 16

Atmospheric pressure at the summit of Mount Everest is about one third the pressure at sea level, which is 760 mm Hg. If oxygen makes up 21% of the atmosphere by volume, the partial pressure of oxygen (PO₂) on Mount Everest is approximately ________.

Accepted Answer

A)  53 mm Hg 
B)  157 mm Hg 
C)  255 mm Hg 
D)  760 mm Hg 
A)  53 mm Hg 
B)  157 mm Hg 
C)  255 mm Hg 
D)  760 mm Hg

Question 17

Most of the carbon dioxide produced by humans is ________.

Accepted Answer

A)  converted to bicarbonate ions 
B)  bound to hemoglobin 
C)  transported in the erythrocytes as carbonic acid 
D)  simply dissolved in the plasma 
A)  converted to bicarbonate ions 
B)  bound to hemoglobin 
C)  transported in the erythrocytes as carbonic acid 
D)  simply dissolved in the plasma

Question 18

In an open circulatory system, blood is ________.

Accepted Answer

A)  always inside of vessels and is under higher pressure than in closed circulatory systems 
B)  not always confined to blood vessels and is under higher pressure than in closed circulatory systems 
C)  always inside of vessels and is under lower pressure than in closed circulatory systems 
D)  not always confined to blood vessels and is under lower pressure than in closed circulatory systems 
A)  always inside of vessels and is under higher pressure than in closed circulatory systems 
B)  not always confined to blood vessels and is under higher pressure than in closed circulatory systems 
C)  always inside of vessels and is under lower pressure than in closed circulatory systems 
D)  not always confined to blood vessels and is under lower pressure than in closed circulatory systems

Question 19

Under identical atmospheric conditions, freshwater ________.

Accepted Answer

A)  has more dissolved oxygen than seawater 
B)  has less dissolved oxygen than seawater 
C)  can hold 10-40 times more carbon dioxide than air 
D)  can hold 10-40 times more oxygen than air 
A)  has more dissolved oxygen than seawater 
B)  has less dissolved oxygen than seawater 
C)  can hold 10-40 times more carbon dioxide than air 
D)  can hold 10-40 times more oxygen than air

Question 20

Hyperventilation (rapid inhalation and exhalation) can result in respiratory alkalosis (increased blood pH). Why?

Accepted Answer

A)  Hyperventilation results in inefficient gas exchange, and not enough oxygen is absorbed by the blood. 
B)  More metabolic waste is released into the blood, thus reducing the pH. 
C)  Rapid breathing depletes the blood of carbon dioxide, thus the blood pH increases. 
D)  Excess production of carbon dioxide decreases the affinity of hemoglobin for oxygen. 
A)  Hyperventilation results in inefficient gas exchange, and not enough oxygen is absorbed by the blood. 
B)  More metabolic waste is released into the blood, thus reducing the pH. 
C)  Rapid breathing depletes the blood of carbon dioxide, thus the blood pH increases. 
D)  Excess production of carbon dioxide decreases the affinity of hemoglobin for oxygen.

Exam 42: Circulation and Gas Exchange

During most daily activities, the human respiration rate is most closely linked to the blood levels of ________.

During aerobic exercise, the partial pressure of oxygen in muscle cells will ________, thus the rate of diffusion of oxygen into the muscle tissue from the blood will ________.

Compared with the interstitial fluid that bathes active muscle cells, blood reaching these cells in arterioles has a

Which of the following mechanisms are used to regulate blood pressure in the closed circulatory system of vertebrates? I.changing the force of heart contraction II.constricting and relaxing smooth muscle in the walls of arterioles III.opening or closing precapillary sphincters

Damage to the sinoatrial node in humans would ________.

How has the avian lung adapted to the metabolic demands of flight?

Which of the following develops the greatest pressure on the blood in the mammalian aorta?

The velocity of blood flow is the lowest in capillaries because ________.

Which of the following events would you predict as carbon dioxide is released from your muscles into the surrounding capillary bed?

Carbon dioxide levels in the blood and cerebrospinal fluid affect pH. This enables the organism to sense a disturbance in gas levels as ________.

Which of the following represents the correct flow of air into the lung of a mammal?

The greatest difference in the concentration of respiratory gases is found in which of the following pairs of mammalian blood vessels?

When the air in a testing chamber is specially mixed so that its oxygen content is 10% and its overall air pressure is 400 mm Hg, then PO₂ is ________.

Compared to mammals that are not adapted for diving, diving mammals ________.

Atmospheric pressure at the summit of Mount Everest is about one third the pressure at sea level, which is 760 mm Hg. If oxygen makes up 21% of the atmosphere by volume, the partial pressure of oxygen (PO₂) on Mount Everest is approximately ________.

Most of the carbon dioxide produced by humans is ________.

In an open circulatory system, blood is ________.

Under identical atmospheric conditions, freshwater ________.

Hyperventilation (rapid inhalation and exhalation) can result in respiratory alkalosis (increased blood pH). Why?

Evolution, the Themes of Biology, and Scientific Inquiry

The Chemical Context of Life

Water and Life

Carbon and the Molecular Diversity of Life

The Structure and Function of Large Biological Molecules

A Tour of the Cell

Membrane Structure and Function

An Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

Cell Communication

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

Gene Expression: From Gene to Protein

Regulation of Gene Expression

Viruses

DNA Tools and Biotechnology

Genomes and Their Evolution

Descent with Modification: A Darwinian View of Life

The Evolution of Populations

The Origin of Species

The History of Life on Earth

Phylogeny and the Tree of Life

Bacteria and Archaea

Protists

Plant Diversity I: How Plants Colonized Land

Plant Diversity II: The Evolution of Seed Plants

Fungi

An Overview of Animal Diversity

An Introduction to Invertebrates

The Origin and Evolution of Vertebrates

Vascular Plant Structure, Growth, and Development

Resource Acquisition and Transport in Vascular Plants

Soil and Plant Nutrition

Angiosperm Reproduction and Biotechnology

Plant Responses to Internal and External Signals

Basic Principles of Animal Form and Function

Animal Nutrition

The Immune System

Osmoregulation and Excretion

Hormones and the Endocrine System

Animal Reproduction

Animal Development

Neurons, Synapses, and Signaling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behavior

An Introduction to Ecology and the Biosphere

Population Ecology

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During aerobic exercise, the partial pressure of oxygen in muscle cells will , thus the rate of diffusion of oxygen into the muscle tissue from the blood will .