Question 1

Carotid bodies are

Accepted Answer

A)  organs located in the medulla region of the brain. 
B)  small organs located in arteries which are sensitive to oxygen levels. 
C)  chemoreceptors which respond to H+ ion concentration. 
D)  central chemoreceptors which contain neurotransmitters which are released in response to changes in the partial pressure of oxygen. 
E)  organs with a primary function to transmit information from the central nervous system to reflect ventilation requirements. 
A)  organs located in the medulla region of the brain. 
B)  small organs located in arteries which are sensitive to oxygen levels. 
C)  chemoreceptors which respond to H+ ion concentration. 
D)  central chemoreceptors which contain neurotransmitters which are released in response to changes in the partial pressure of oxygen. 
E)  organs with a primary function to transmit information from the central nervous system to reflect ventilation requirements.

Question 2

In mammals

Accepted Answer

A)  lungs are stiff but have high compliance. 
B)  positive pressure in the pleural cavity prevents the lung from collapsing. 
C)  inspiration is an active muscular process. 
D)  inspiration is achieved with a positive pressure. 
E)  lungs are in a cavity within the abdomen. 
A)  lungs are stiff but have high compliance. 
B)  positive pressure in the pleural cavity prevents the lung from collapsing. 
C)  inspiration is an active muscular process. 
D)  inspiration is achieved with a positive pressure. 
E)  lungs are in a cavity within the abdomen.

Question 3

Tidal ventilation is feasible in large, air-breathing animals because

Accepted Answer

A)  O2 is more available in air than water. 
B)  O2 is more available in water than air. 
C)  it enables countercurrent gas exchange. 
D)  it increases the partial pressure of O2 in the lungs. 
E)  it increases the partial pressure of O2 in the lung. 
A)  O2 is more available in air than water. 
B)  O2 is more available in water than air. 
C)  it enables countercurrent gas exchange. 
D)  it increases the partial pressure of O2 in the lungs. 
E)  it increases the partial pressure of O2 in the lung.

Question 4

Which of the following is used by birds during respiration?

Accepted Answer

A)  Countercurrent exchange. 
B)  Co-current exchange. 
C)  Cross-current exchange. 
D)  Large air capillaries. 
E)  An aspirating pump to create negative pressure in the lung. 
A)  Countercurrent exchange. 
B)  Co-current exchange. 
C)  Cross-current exchange. 
D)  Large air capillaries. 
E)  An aspirating pump to create negative pressure in the lung.

Question 5

Gills do not function well in air because

Accepted Answer

A)  they have a large surface area. 
B)  they are heavily chitinised. 
C)  they are thin-walled and heavy. 
D)  they rely on muscular action. 
E)  surface tension would increase and decrease gas exchange. 
A)  they have a large surface area. 
B)  they are heavily chitinised. 
C)  they are thin-walled and heavy. 
D)  they rely on muscular action. 
E)  surface tension would increase and decrease gas exchange.

Question 6

The chloride shift associated with the transport of CO2 in mammals

Accepted Answer

A)  allows large amounts of hydrogen carbonate to be exchanged between erythrocytes and plasma. 
B)  maintains the electrical balance between plasma and erythrocytes. 
C)  requires the movement of Cl- ions into the erythrocyte in lungs to enable the diffusion of CO2 out of the erythrocyte. 
D)  is necessary to balance the H+ ions produced from the dissociation of H2CO2. 
E)  All of the answers are correct. 
A)  allows large amounts of hydrogen carbonate to be exchanged between erythrocytes and plasma. 
B)  maintains the electrical balance between plasma and erythrocytes. 
C)  requires the movement of Cl- ions into the erythrocyte in lungs to enable the diffusion of CO2 out of the erythrocyte. 
D)  is necessary to balance the H+ ions produced from the dissociation of H2CO2. 
E)  All of the answers are correct.

Question 7

Increasing altitude has which of the following effects on air?

Accepted Answer

A)  The proportion of oxygen decreases. 
B)  The partial pressure of oxygen decreases. 
C)  The partial pressure of oxygen increases. 
D)  The concentration of oxygen increases. 
E)  The proportion of oxygen increases. 
A)  The proportion of oxygen decreases. 
B)  The partial pressure of oxygen decreases. 
C)  The partial pressure of oxygen increases. 
D)  The concentration of oxygen increases. 
E)  The proportion of oxygen increases.

Question 8

An animal in distress is having trouble breathing. Closer inspection reveals it appears to have a punctured thoracic wall. The reason for the animals distress is therefore

Accepted Answer

A)  a thorax embolism. 
B)  a pleural cavity. 
C)  a collapsed lung. 
D)  lack of lung expiration. 
E)  a passive embolar cavitation. 
A)  a thorax embolism. 
B)  a pleural cavity. 
C)  a collapsed lung. 
D)  lack of lung expiration. 
E)  a passive embolar cavitation.

Question 9

The Haldane effect

Accepted Answer

A)  relates to the effect of CO2 concentration on acid-base homeostasis. 
B)  is a property of haemoglobin where oxygenated blood have the ability to carry more CO2. 
C)  is not relevant to invertebrates. 
D)  means that the more deoxygenated the haemoglobin, the better it binds with oxygen. 
E)  means that the more deoxygenated the haemoglobin, the better it binds with CO2. 
A)  relates to the effect of CO2 concentration on acid-base homeostasis. 
B)  is a property of haemoglobin where oxygenated blood have the ability to carry more CO2. 
C)  is not relevant to invertebrates. 
D)  means that the more deoxygenated the haemoglobin, the better it binds with oxygen. 
E)  means that the more deoxygenated the haemoglobin, the better it binds with CO2.

Question 10

In aquatic invertebrates

Accepted Answer

A)  ventilation is always achieved by the beating of the swimming appendages. 
B)  gas exchange occurs via papulae in most crustaceans. 
C)  gills are rarely located in chambers. 
D)  ventilation is essential for gas exchange in papulae. 
E)  gills are outgrowths of the body surface. 
A)  ventilation is always achieved by the beating of the swimming appendages. 
B)  gas exchange occurs via papulae in most crustaceans. 
C)  gills are rarely located in chambers. 
D)  ventilation is essential for gas exchange in papulae. 
E)  gills are outgrowths of the body surface.

Question 11

Amphibians

Accepted Answer

A)  use only their gills for gas exchange. 
B)  ventilate their lungs continuously using negative pressure. 
C)  rarely use their skin for gas exchange. 
D)  absorb oxygen through their skin and loose CO2 through their gills. 
E)  characteristically absorb O2 in the lungs and lose carbon dioxide through the skin. 
A)  use only their gills for gas exchange. 
B)  ventilate their lungs continuously using negative pressure. 
C)  rarely use their skin for gas exchange. 
D)  absorb oxygen through their skin and loose CO2 through their gills. 
E)  characteristically absorb O2 in the lungs and lose carbon dioxide through the skin.

Question 12

In water animals, the direction in which water and blood flow relative to one another

Accepted Answer

A)  does not affect the efficiency of gas exchange. 
B)  gives rapid equilibration dependent only on the surface area of contact. 
C)  provides efficiency dependent of the type of ventilation. 
D)  achieves greater efficiency by countercurrent flow. 
E)  achieves greater efficiency by co-current flow. 
A)  does not affect the efficiency of gas exchange. 
B)  gives rapid equilibration dependent only on the surface area of contact. 
C)  provides efficiency dependent of the type of ventilation. 
D)  achieves greater efficiency by countercurrent flow. 
E)  achieves greater efficiency by co-current flow.

Question 13

Air and water have very different properties as respiratory media. Which of the following is CORRECT?

Accepted Answer

A)  The solubility of O2 in air and water is the same. 
B)  O2 is more soluble in water than CO2. 
C)  Compared to water, air provides a greater resistance to diffusion of both O2 and CO2. 
D)  The capacitance of O2 and CO2 in air is the same. 
E)  The capacitance of air for CO2 is greater than for O2. 
A)  The solubility of O2 in air and water is the same. 
B)  O2 is more soluble in water than CO2. 
C)  Compared to water, air provides a greater resistance to diffusion of both O2 and CO2. 
D)  The capacitance of O2 and CO2 in air is the same. 
E)  The capacitance of air for CO2 is greater than for O2.

Question 14

The rate of diffusion of a gas across a membrane is

Accepted Answer

A)  dependent on a partial pressure gradient. 
B)  the same for all types of membranes. 
C)  independent of membrane thickness. 
D)  proportional to the thickness of the membrane. 
E)  All of the answers are correct. 
A)  dependent on a partial pressure gradient. 
B)  the same for all types of membranes. 
C)  independent of membrane thickness. 
D)  proportional to the thickness of the membrane. 
E)  All of the answers are correct.

Question 15

Mammalian lungs

Accepted Answer

A)  are basically a dense capillary network encased by a thin epithelial layer. 
B)  provide a small diffusion distance between air and blood at the exchange surface. 
C)  are a mass of branching ducts and cupped-shaped chambers. 
D)  have gas exchange in alveolar ducts. 
E)  All of the answers are correct. 
A)  are basically a dense capillary network encased by a thin epithelial layer. 
B)  provide a small diffusion distance between air and blood at the exchange surface. 
C)  are a mass of branching ducts and cupped-shaped chambers. 
D)  have gas exchange in alveolar ducts. 
E)  All of the answers are correct.

Question 16

Animals use O2 and CO2 (pH) levels to regulate ventilation. Which of the following is CORRECT?

Accepted Answer

A)  Water breathers primarily regulate ventilation in response to changes in CO2 because their internal levels of CO2 are very similar to water. 
B)  Water breathers primarily regulate ventilation in response to changes in CO2 because O2 is readily available from water. 
C)  Air breathers primarily regulate ventilation in response to changes in CO2 because their internal levels of CO2 are higher than for air. 
D)  Water breathers primarily regulate ventilation in response to O2 changes as the level of O2 in water is low. 
E)  Air breathers primarily regulate ventilation in response to changes in O2 because O2 is readily available from air. 
A)  Water breathers primarily regulate ventilation in response to changes in CO2 because their internal levels of CO2 are very similar to water. 
B)  Water breathers primarily regulate ventilation in response to changes in CO2 because O2 is readily available from water. 
C)  Air breathers primarily regulate ventilation in response to changes in CO2 because their internal levels of CO2 are higher than for air. 
D)  Water breathers primarily regulate ventilation in response to O2 changes as the level of O2 in water is low. 
E)  Air breathers primarily regulate ventilation in response to changes in O2 because O2 is readily available from air.

Question 17

Many small organisms meet their O2 requirements by gas diffusion across their membranes. What is a simple, effective method for replenishing O2 levels in a small organism's immediate environment?

Accepted Answer

A)  Increase the O2 levels in the boundary layer. 
B)  Decrease metabolic rates to decrease O2 use. 
C)  Decrease the PO2 pressure gradient across the boundary layer. 
D)  Decrease the partial pressure gradient for diffusion. 
E)  Mix and/or replace water in the boundary layer surrounding the organism. 
A)  Increase the O2 levels in the boundary layer. 
B)  Decrease metabolic rates to decrease O2 use. 
C)  Decrease the PO2 pressure gradient across the boundary layer. 
D)  Decrease the partial pressure gradient for diffusion. 
E)  Mix and/or replace water in the boundary layer surrounding the organism.

Question 18

In general, you would expect to find the greatest surface area (relative to size) for gas exchange in animals that are

Accepted Answer

A)  ectothermic. 
B)  active and endothermic. 
C)  sedentary and endothermic. 
D)  vertebrates. 
E)  invertebrates. 
A)  ectothermic. 
B)  active and endothermic. 
C)  sedentary and endothermic. 
D)  vertebrates. 
E)  invertebrates.

Question 19

An unknown fish is analysed and found to be devoid of both buccal and opercular muscle systems, but has powerful locomotive musculature. This fish must therefore ventilate its gills by

Accepted Answer

A)  Cutaneous respiration 
B)  Ram ventilation 
C)  Simple gill ventilation 
D)  Chambered gill respiration 
E)  Metabolic oxygenation 
A)  Cutaneous respiration 
B)  Ram ventilation 
C)  Simple gill ventilation 
D)  Chambered gill respiration 
E)  Metabolic oxygenation

Question 20

Countercurrent gas exchange

Accepted Answer

A)  is characteristic of terrestrial organisms because O2 is more available in air than water. 
B)  involves circulatory fluid with a high partial pressure of O2 leaving the gill filament encountering water with a higher partial pressure of O2 entering the filament. 
C)  occurs in sponges due to choanocytes lining the surface. 
D)  is more efficient than co-current exchange because water and circulatory fluid reach equilibrium at a partial pressure of O2 significantly lower than that of water. 
E)  is not possible for fish because their gill chambers are full of lamellae. 
A)  is characteristic of terrestrial organisms because O2 is more available in air than water. 
B)  involves circulatory fluid with a high partial pressure of O2 leaving the gill filament encountering water with a higher partial pressure of O2 entering the filament. 
C)  occurs in sponges due to choanocytes lining the surface. 
D)  is more efficient than co-current exchange because water and circulatory fluid reach equilibrium at a partial pressure of O2 significantly lower than that of water. 
E)  is not possible for fish because their gill chambers are full of lamellae.

Exam 23: Gas Exchange in Animals

Carotid bodies are

In mammals

Tidal ventilation is feasible in large, air-breathing animals because

Which of the following is used by birds during respiration?

Gills do not function well in air because

The chloride shift associated with the transport of CO2 in mammals

Increasing altitude has which of the following effects on air?

An animal in distress is having trouble breathing. Closer inspection reveals it appears to have a punctured thoracic wall. The reason for the animals distress is therefore

The Haldane effect

In aquatic invertebrates

Amphibians

In water animals, the direction in which water and blood flow relative to one another

Air and water have very different properties as respiratory media. Which of the following is CORRECT?

The rate of diffusion of a gas across a membrane is

Mammalian lungs

Animals use O2 and CO2 (pH) levels to regulate ventilation. Which of the following is CORRECT?

Many small organisms meet their O2 requirements by gas diffusion across their membranes. What is a simple, effective method for replenishing O2 levels in a small organism's immediate environment?

In general, you would expect to find the greatest surface area (relative to size) for gas exchange in animals that are

An unknown fish is analysed and found to be devoid of both buccal and opercular muscle systems, but has powerful locomotive musculature. This fish must therefore ventilate its gills by

Countercurrent gas exchange

Nature of Molecules

Biomolecules

The Chemistry of Life

Functioning Cells

Movement Across Membranes

Harvesting Energy

Cells, Tissues and Signals

Cell Division

Inheritance

Genes, Chromosomes and Dna

The Genetic Code

Gene Expression

Genomes, Mutation and Cancer

Viruses

Genetic Engineering and Biotechnology

Reproduction, Growth and Development of Flowering Plants

Structure of Plants

Plant Nutrition, Transport and Adaptation to Stress

Plant Hormones and Growth Responses

Animal Reproduction

Animal Development

Homeostasis: Water, Solutes and Excretion

Circulation

Metabolism, Temperature Regulation and Environmental Stress

Animal and Human Nutrition

Innate Defences and the Immune System

Hormonal Control in Animals

Nervous Systems

Animal Movement

Animal Behaviour

Evolving Life

Evolving Earth

Mechanisms of Evolution

Bacteria

The Protists

Plants

Fungi

Simple Animals: Sponges to Flatworms

Annelids, Molluscs, Nematodes and Arthropods

Echinoderms and Chordates

Australian Biota

Population Ecology

Living in Communities

Ecosystems

Human Impacts

Filters

The chloride shift associated with the transport of CO₂ in mammals

Animals use O₂ and CO₂ (pH) levels to regulate ventilation. Which of the following is CORRECT?

Many small organisms meet their O₂ requirements by gas diffusion across their membranes. What is a simple, effective method for replenishing O₂ levels in a small organism's immediate environment?