Question 1

Countercurrent exchange is evident in

Accepted Answer

A) the flow of water across the gills of a fish and that of blood within those gills. 
B) the flow of blood in the dorsal vessel of an insect and that of air within its tracheae. 
C) the flow of air within the primary bronchi of a human and that of blood within the pulmonary veins. 
D) the flow of water across the skin of a frog and that of blood within the ventricle of its heart. 
E) the flow of fluid out of the arterial end of a capillary and that of fluid back into the venous end of the same capillary. 
A) the flow of water across the gills of a fish and that of blood within those gills. 
B) the flow of blood in the dorsal vessel of an insect and that of air within its tracheae. 
C) the flow of air within the primary bronchi of a human and that of blood within the pulmonary veins. 
D) the flow of water across the skin of a frog and that of blood within the ventricle of its heart. 
E) the flow of fluid out of the arterial end of a capillary and that of fluid back into the venous end of the same capillary.

Question 2

The hemocyanin of arthropods and molluscs differ from the hemoglobin of mammals in that

Accepted Answer

A) the oxygen dissociation curve for hemocyanin is linear. 
B) hemocyanin carries appreciably more carbon dioxide. 
C) hemocyanin has protein coupled to copper rather than iron. 
D) the protein of hemocyanin is not bound to metal. 
E) hemocyanin includes cyanic acid. 
A) the oxygen dissociation curve for hemocyanin is linear. 
B) hemocyanin carries appreciably more carbon dioxide. 
C) hemocyanin has protein coupled to copper rather than iron. 
D) the protein of hemocyanin is not bound to metal. 
E) hemocyanin includes cyanic acid.

Question 3

An increase from pH 7.2 to pH 7.4 around hemoglobin causes

Accepted Answer

A) hemoglobin to release all bound oxygen molecules. 
B) an increase in the affinity of hemoglobin to bind oxygen molecules. 
C) hemoglobin to denature. 
D) an increase in the binding of H⁺ by hemoglobin. 
E) hemoglobin to more readily give up its oxygen molecules. 
A) hemoglobin to release all bound oxygen molecules. 
B) an increase in the affinity of hemoglobin to bind oxygen molecules. 
C) hemoglobin to denature. 
D) an increase in the binding of H⁺ by hemoglobin. 
E) hemoglobin to more readily give up its oxygen molecules.

Question 4

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

Accepted Answer

A) the brain directly measures and monitors carbon dioxide 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. 
E) the medulla oblongata is able to control the concentration of bicarbonate ions in the blood. 
A) the brain directly measures and monitors carbon dioxide 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. 
E) the medulla oblongata is able to control the concentration of bicarbonate ions in the blood.

Question 5

The semilunar valves of the mammalian heart

Accepted Answer

A) are the route by which blood flows from the atria to the ventricles. 
B) are found only on the right side of the heart. 
C) are the attachment site where the pulmonary veins empty into the heart. 
D) prevent backflow of blood in the aorta and pulmonary arteries. 
E) are at the places where the anterior and posterior venae cavae empty into the heart. 
A) are the route by which blood flows from the atria to the ventricles. 
B) are found only on the right side of the heart. 
C) are the attachment site where the pulmonary veins empty into the heart. 
D) prevent backflow of blood in the aorta and pulmonary arteries. 
E) are at the places where the anterior and posterior venae cavae empty into the heart.

Question 6

An "internal reservoir" of oxygen in rested muscle is found in oxygen molecules bound to

Accepted Answer

A) hemoglobin. 
B) bicarbonate ions. 
C) carbonic acid. 
D) actin and myosin. 
E) myoglobin. 
A) hemoglobin. 
B) bicarbonate ions. 
C) carbonic acid. 
D) actin and myosin. 
E) myoglobin.

Question 7

Blood returning to the mammalian heart in a pulmonary vein drains first into the

Accepted Answer

A) vena cava. 
B) left atrium. 
C) right atrium. 
D) left ventricle. 
E) right ventricle. 
A) vena cava. 
B) left atrium. 
C) right atrium. 
D) left ventricle. 
E) right ventricle.

Question 8

The circulatory system of bony fishes,rays,and sharks is similar to

Accepted Answer

A) that of birds, with a four-chambered heart. 
B) the portal systems of mammals, where two capillary beds occur sequentially, without passage of blood through a pumping chamber. 
C) that of reptiles, with one pumping chamber driving blood flow to a gas-exchange organ, and a different pumping chamber driving blood to the rest of the circulation. 
D) that of sponges, in which gas exchange in all cells occurs directly with the external environment. 
E) that of humans, in which there are four pumping chambers to drive blood flow. 
A) that of birds, with a four-chambered heart. 
B) the portal systems of mammals, where two capillary beds occur sequentially, without passage of blood through a pumping chamber. 
C) that of reptiles, with one pumping chamber driving blood flow to a gas-exchange organ, and a different pumping chamber driving blood to the rest of the circulation. 
D) that of sponges, in which gas exchange in all cells occurs directly with the external environment. 
E) that of humans, in which there are four pumping chambers to drive blood flow.

Question 9

Which of the following pairs of mammalian blood vessels has blood that is the least similar in its gas content?

Accepted Answer

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

Question 10

The meshwork that forms the fabric of a blood clot is

Accepted Answer

A) chymotrypsin. 
B) fibrin. 
C) thrombin. 
D) prothrombin. 
E) collagen. 
A) chymotrypsin. 
B) fibrin. 
C) thrombin. 
D) prothrombin. 
E) collagen.

Question 11

A patient with a blood pressure of 120/75,a pulse rate of 40 beats/minute,a stroke volume of 70 mL/beat,and a respiratory rate of 25 breaths/minute will have a cardiac output of

Accepted Answer

A) 500 mL/minute. 
B) 1000 mL/minute. 
C) 1750 mL/minute. 
D) 2800 mL/minute. 
E) 4800 mL/minute. 
A) 500 mL/minute. 
B) 1000 mL/minute. 
C) 1750 mL/minute. 
D) 2800 mL/minute. 
E) 4800 mL/minute.

Question 12

Atmospheric pressure at sea level is equal to a column of 760 mm Hg.Oxygen makes up 21% of the atmosphere by volume.The partial pressure of oxygen (PO₂)in such conditions is

Accepted Answer

A) 160 mm Hg. 
B) 16 mm Hg. 
C) 120/75. 
D) 21/760. 
E) 760/21. 
A) 160 mm Hg. 
B) 16 mm Hg. 
C) 120/75. 
D) 21/760. 
E) 760/21.

Question 13

Hydrogen ions produced within human red blood cells are prevented from significantly lowering plasma pH because they bind to

Accepted Answer

A) hemoglobin. 
B) plasma proteins. 
C) carbon dioxide. 
D) carbonic acid. 
E) plasma buffers. 
A) hemoglobin. 
B) plasma proteins. 
C) carbon dioxide. 
D) carbonic acid. 
E) plasma buffers.

Question 14

Dialysis patients,who will have blood withdrawn,dialyzed,then replaced,are always weighed when they enter the facility and then weighed carefully again before they leave,because

Accepted Answer

A) even small changes in body weight may signify changes in blood volume and therefore blood pressure. 
B) many people who have dialysis are diabetic and must control their weight carefully. 
C) dialysis removes blood proteins and these weigh more than other blood components. 
D) dialysis is likely to cause edema and such swelling must be controlled. 
E) reclining posture during dialysis can cause a tendency for weight gain. 
A) even small changes in body weight may signify changes in blood volume and therefore blood pressure. 
B) many people who have dialysis are diabetic and must control their weight carefully. 
C) dialysis removes blood proteins and these weigh more than other blood components. 
D) dialysis is likely to cause edema and such swelling must be controlled. 
E) reclining posture during dialysis can cause a tendency for weight gain.

Question 15

At an atmospheric pressure of 870 mm Hg of 21% oxygen,the partial pressure of oxygen is

Accepted Answer

A) 100 mm Hg. 
B) 127 mm Hg. 
C) 151 mm Hg. 
D) 182 mm Hg. 
E) 219 mm Hg. 
A) 100 mm Hg. 
B) 127 mm Hg. 
C) 151 mm Hg. 
D) 182 mm Hg. 
E) 219 mm Hg.

Question 16

Use the following information to answer the next few questions.
A paramedic arrives at a middle-aged man's home.The man is complaining of chest pain and shortness of breath.Upon examination of his medicine cabinet,the paramedic finds prescription bottles of statins and aspirin.
-Which ailment is the man most likely suffering from?

Accepted Answer

A) Sickle cell disease. 
B) Altitude sickness. 
C) Thrombocytopenia. 
D) Cardiovascular disease. 
E) Hemophilia. 
A) Sickle cell disease. 
B) Altitude sickness. 
C) Thrombocytopenia. 
D) Cardiovascular disease. 
E) Hemophilia.

Question 17

Cyanide poisons mitochondria by blocking the final step in the electron transport chain.Human red blood cells placed in an isotonic solution containing cyanide are likely to

Accepted Answer

A) retain the normal cell shape, but the mitochondria will be poisoned. 
B) lyse as the cyanide concentration increases inside the cell. 
C) switch to anaerobic metabolism. 
D) become unable to carry oxygen. 
E) be unaffected. 
A) retain the normal cell shape, but the mitochondria will be poisoned. 
B) lyse as the cyanide concentration increases inside the cell. 
C) switch to anaerobic metabolism. 
D) become unable to carry oxygen. 
E) be unaffected.

Question 18

The sun shining on a tidal pool during a hot day heats the water.As some water evaporates,the pool becomes saltier,causing

Accepted Answer

A) a decrease in its carbon dioxide content. 
B) a decrease in its oxygen content. 
C) an increase in its ability to sustain aerobic organisms. 
D) a decrease in the water's density. 
E) a decrease in the movement of the water molecules. 
A) a decrease in its carbon dioxide content. 
B) a decrease in its oxygen content. 
C) an increase in its ability to sustain aerobic organisms. 
D) a decrease in the water's density. 
E) a decrease in the movement of the water molecules.

Question 19

At sea level,atmospheric pressure is 760 mm Hg.Oxygen gas is approximately 21% of the total gases in the atmosphere,so the approximate partial pressure of oxygen is

Accepted Answer

A) 0)2 mm Hg. 
B) 20.0 mm Hg. 
C) 76.0 mm Hg. 
D) 160.0 mm Hg. 
E) 508.0 mm Hg. 
A) 0)2 mm Hg. 
B) 20.0 mm Hg. 
C) 76.0 mm Hg. 
D) 160.0 mm Hg. 
E) 508.0 mm Hg.

Question 20

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) 21 mm Hg. 
E) 4 mm Hg. 
A) 400 mm Hg. 
B) 82 mm Hg. 
C) 40 mm Hg. 
D) 21 mm Hg. 
E) 4 mm Hg.

Exam 42: Circulation and Gas Exchange

Countercurrent exchange is evident in

The hemocyanin of arthropods and molluscs differ from the hemoglobin of mammals in that

An increase from pH 7.2 to pH 7.4 around hemoglobin causes

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

The semilunar valves of the mammalian heart

An "internal reservoir" of oxygen in rested muscle is found in oxygen molecules bound to

Blood returning to the mammalian heart in a pulmonary vein drains first into the

The circulatory system of bony fishes,rays,and sharks is similar to

Which of the following pairs of mammalian blood vessels has blood that is the least similar in its gas content?

The meshwork that forms the fabric of a blood clot is

A patient with a blood pressure of 120/75,a pulse rate of 40 beats/minute,a stroke volume of 70 mL/beat,and a respiratory rate of 25 breaths/minute will have a cardiac output of

Atmospheric pressure at sea level is equal to a column of 760 mm Hg.Oxygen makes up 21% of the atmosphere by volume.The partial pressure of oxygen (PO₂)in such conditions is

Hydrogen ions produced within human red blood cells are prevented from significantly lowering plasma pH because they bind to

Dialysis patients,who will have blood withdrawn,dialyzed,then replaced,are always weighed when they enter the facility and then weighed carefully again before they leave,because

At an atmospheric pressure of 870 mm Hg of 21% oxygen,the partial pressure of oxygen is

Cyanide poisons mitochondria by blocking the final step in the electron transport chain.Human red blood cells placed in an isotonic solution containing cyanide are likely to

The sun shining on a tidal pool during a hot day heats the water.As some water evaporates,the pool becomes saltier,causing

At sea level,atmospheric pressure is 760 mm Hg.Oxygen gas is approximately 21% of the total gases in the atmosphere,so the approximate partial pressure of oxygen is

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

Introduction: Evolution and Themes of Biology

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

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

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 Signalling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behaviour

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

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