TEST BANK
Principles of Animal Physiology
3rd Edition
Christopher D. Moyes & Patricia M. Schulte
ISBN13: 9780137335435
Table of Contents
Chapter 1. Introduction to Physiological Principles
Chapter 2. Physiological Evolution of Animals (NEW)
Chapter 3. Chemistry, Biochemistry, and Cell Physiology
Chapter 4. Cell Signaling and Endocrine Regulation
Chapter 5. Neuron Structure and Function
Chapter 6. Cellular Movement and Muscles
Chapter 7. Sensory Systems
Chapter 8. Functional Organization of Nervous Systems
Chapter 9. Circulatory Systems
Chapter 10. Immune Systems (NEW)
,Chapter 11. Respiratory Systems
Chapter 12. Locomotion
Chapter 13. Ion and Water Balance
Chapter 14. Digestion and Energy Metabolism
Chapter 15. Thermal Physiology
Chapter 16. Reproductive Physiology
CHAPTER NO. 01: INTRODUCTION TO PHYSIOLOGICAL PRINCIPLES
Answers to Review Questions
1. Where would organelles such as the mitochondrion fit in the levels of organization shown in Figure 1.3?
Answer
Organelles such as mitochondria would fit between the molecular and the cellular levels in Figure 1.3. Molecules
work together in complex biochemical pathways to form the complex structures that are assembled to make
organelles. These organelles are parts of a cell.
2. What is the Krogh principle, and why is it useful for animal physiologists?
Answer
The Krogh Principle states that for every biological problem there is an organism on which it can be most
conveniently studied. This means that medical physiologists interested in a function in humans (or veterinary
physiologists interested in cows) might choose to study these functions in an animal such as a mouse, because they are
much smaller and easier to maintain.
3. All organisms have a maximum temperature at which they can function. Suggest a possible physical basis for this
observation.
Answer
The maximum temperature that an organism can function at must be the lowest temperature at which a critical process
required to sustain life fails. Not all physiological functions are likely to fail at exactly the same temperature, but when
a critical process fails, life will end. Processes could fail at high temperatures for a variety of reasons, but ultimately
this failure must be due to changes in intermolecular interactions at high temperatures.
4. How might size-related changes in surface area-to-volume ratios affect physiological functions?
Answer
Surface area increases less with size than does volume, so surface area for exchange becomes limiting as size
increases, unless there is a change in shape. This pattern explains why physiological systems such as the respiratory
system have extremely high surface area compared with their volume. This increases the area available for gas
exchange.
5. What are three fundamental requirements for adaptive evolution of a trait to occur?
Answer
For adaptive evolution to occur:
1. There must be variation among individuals in the trait.
2. The trait must be heritable.
3. The trait must increase the fitness.
,6. Are the eyes of vertebrates and cephalopod mollusks homologous or analogous? Justify your answer.
Answer
The eyes of vertebrates and cephalopod mollusks are analogous. Both are camera-type eyes that can form a focused
image, but they arose independently from different ancestors that lacked camera-type eyes. Thus, they did not share
a common ancestor and cannot be homologous, despite their similarity of function.
7. What is the main benefit of having antagonistic controls in physiological systems?
Answer
Antagonistic controls allow more precise control over a physiological system by having two separate control
mechanisms: one that increases, and one that decreases, the activity of the system. This is analogous to having both
a brake and an accelerator on a car.
8. Explain why a positive feedback loop is unlikely to be involved in a control system that maintains homeostasis.
Answer
Positive feedback loops are organized so that the output of the system tends to increase the activity of the system.
This results in a rapid response and an amplification of the output of the system, resulting in a large response to a
small stimulus. This control mechanism is unlikely to be appropriate for a control system that maintains homeostasis,
because homeostasis involves maintaining the system within a narrow range around the set point.
, Answers to Concept Check Questions
1. How would you define physiology?
Answer
It is the study of the functioning of biological structures and systems, or how organisms work.
2. What is a model organism in the context of physiological research?
Answer
The August Krogh Principle suggests that “for any biological question, there is an organism on which it can be most
conveniently studied.” A model organism is a convenient animal on which to study a biological question. Squid, for
example, was an early model to study neuronal function because of the size of its giant axon.
3. Why do the rates of biochemical reactions increase as temperature increases? Do they do so infinitely?
Answer
Temperature increases the thermal energy of molecules and increases the number of collisions between molecules.
Because most reactions require molecular collisions, increasing the rate of collisions will increase the rate of
reactions. This increase does not continue to infinity as temperature increases because at high temperatures many of
the intermolecular bonds that stabilize protein structure start to break, causing proteins to unfold and denature. When
proteins are unfolded they are unable to perform their functions. Because most biochemical reactions only occur at
high rates because of the actions of protein catalysts, reaction rates decline when the catalysts begin to denature.
4. What is allometric scaling?
Answer
Some processes or structures change in direct proportion to body mass, which is called isometric scaling. If the
process or structure changes disproportionately with body mass, it is considered to scale allometrically.
5. What is an adaptation?
Answer
An adaptation is a trait that arose via a process such as natural selection and that causes an increase in reproductive
success.
6. Distinguish between homology and analogy.
Answer
Homology describes a pattern where a trait that is present in two taxa is inherited from a common ancestor. These
traits may or may not be similar in appearance and function in the two taxa. For example, bird wings and human arms
appear to be quite different, but they are actually homologous because they both evolved from the forelimbs of a four-
legged ancestor.
Principles of Animal Physiology
3rd Edition
Christopher D. Moyes & Patricia M. Schulte
ISBN13: 9780137335435
Table of Contents
Chapter 1. Introduction to Physiological Principles
Chapter 2. Physiological Evolution of Animals (NEW)
Chapter 3. Chemistry, Biochemistry, and Cell Physiology
Chapter 4. Cell Signaling and Endocrine Regulation
Chapter 5. Neuron Structure and Function
Chapter 6. Cellular Movement and Muscles
Chapter 7. Sensory Systems
Chapter 8. Functional Organization of Nervous Systems
Chapter 9. Circulatory Systems
Chapter 10. Immune Systems (NEW)
,Chapter 11. Respiratory Systems
Chapter 12. Locomotion
Chapter 13. Ion and Water Balance
Chapter 14. Digestion and Energy Metabolism
Chapter 15. Thermal Physiology
Chapter 16. Reproductive Physiology
CHAPTER NO. 01: INTRODUCTION TO PHYSIOLOGICAL PRINCIPLES
Answers to Review Questions
1. Where would organelles such as the mitochondrion fit in the levels of organization shown in Figure 1.3?
Answer
Organelles such as mitochondria would fit between the molecular and the cellular levels in Figure 1.3. Molecules
work together in complex biochemical pathways to form the complex structures that are assembled to make
organelles. These organelles are parts of a cell.
2. What is the Krogh principle, and why is it useful for animal physiologists?
Answer
The Krogh Principle states that for every biological problem there is an organism on which it can be most
conveniently studied. This means that medical physiologists interested in a function in humans (or veterinary
physiologists interested in cows) might choose to study these functions in an animal such as a mouse, because they are
much smaller and easier to maintain.
3. All organisms have a maximum temperature at which they can function. Suggest a possible physical basis for this
observation.
Answer
The maximum temperature that an organism can function at must be the lowest temperature at which a critical process
required to sustain life fails. Not all physiological functions are likely to fail at exactly the same temperature, but when
a critical process fails, life will end. Processes could fail at high temperatures for a variety of reasons, but ultimately
this failure must be due to changes in intermolecular interactions at high temperatures.
4. How might size-related changes in surface area-to-volume ratios affect physiological functions?
Answer
Surface area increases less with size than does volume, so surface area for exchange becomes limiting as size
increases, unless there is a change in shape. This pattern explains why physiological systems such as the respiratory
system have extremely high surface area compared with their volume. This increases the area available for gas
exchange.
5. What are three fundamental requirements for adaptive evolution of a trait to occur?
Answer
For adaptive evolution to occur:
1. There must be variation among individuals in the trait.
2. The trait must be heritable.
3. The trait must increase the fitness.
,6. Are the eyes of vertebrates and cephalopod mollusks homologous or analogous? Justify your answer.
Answer
The eyes of vertebrates and cephalopod mollusks are analogous. Both are camera-type eyes that can form a focused
image, but they arose independently from different ancestors that lacked camera-type eyes. Thus, they did not share
a common ancestor and cannot be homologous, despite their similarity of function.
7. What is the main benefit of having antagonistic controls in physiological systems?
Answer
Antagonistic controls allow more precise control over a physiological system by having two separate control
mechanisms: one that increases, and one that decreases, the activity of the system. This is analogous to having both
a brake and an accelerator on a car.
8. Explain why a positive feedback loop is unlikely to be involved in a control system that maintains homeostasis.
Answer
Positive feedback loops are organized so that the output of the system tends to increase the activity of the system.
This results in a rapid response and an amplification of the output of the system, resulting in a large response to a
small stimulus. This control mechanism is unlikely to be appropriate for a control system that maintains homeostasis,
because homeostasis involves maintaining the system within a narrow range around the set point.
, Answers to Concept Check Questions
1. How would you define physiology?
Answer
It is the study of the functioning of biological structures and systems, or how organisms work.
2. What is a model organism in the context of physiological research?
Answer
The August Krogh Principle suggests that “for any biological question, there is an organism on which it can be most
conveniently studied.” A model organism is a convenient animal on which to study a biological question. Squid, for
example, was an early model to study neuronal function because of the size of its giant axon.
3. Why do the rates of biochemical reactions increase as temperature increases? Do they do so infinitely?
Answer
Temperature increases the thermal energy of molecules and increases the number of collisions between molecules.
Because most reactions require molecular collisions, increasing the rate of collisions will increase the rate of
reactions. This increase does not continue to infinity as temperature increases because at high temperatures many of
the intermolecular bonds that stabilize protein structure start to break, causing proteins to unfold and denature. When
proteins are unfolded they are unable to perform their functions. Because most biochemical reactions only occur at
high rates because of the actions of protein catalysts, reaction rates decline when the catalysts begin to denature.
4. What is allometric scaling?
Answer
Some processes or structures change in direct proportion to body mass, which is called isometric scaling. If the
process or structure changes disproportionately with body mass, it is considered to scale allometrically.
5. What is an adaptation?
Answer
An adaptation is a trait that arose via a process such as natural selection and that causes an increase in reproductive
success.
6. Distinguish between homology and analogy.
Answer
Homology describes a pattern where a trait that is present in two taxa is inherited from a common ancestor. These
traits may or may not be similar in appearance and function in the two taxa. For example, bird wings and human arms
appear to be quite different, but they are actually homologous because they both evolved from the forelimbs of a four-
legged ancestor.
