Question 1

Which statement about actin is true?

Accepted Answer

A)  Two strands of tropomyosin are twisted around polymerized actin. 
B)  Actin carries out the power stroke motion that allows filaments to slide during contraction. 
C)  Actin is the only protein making up thin filaments in a muscle fiber. 
D)  Troponin forms the head of the actin molecule. 
E)  Tropomyosin has ATPase activity and interacts with the actin. 
A)  Two strands of tropomyosin are twisted around polymerized actin. 
B)  Actin carries out the power stroke motion that allows filaments to slide during contraction. 
C)  Actin is the only protein making up thin filaments in a muscle fiber. 
D)  Troponin forms the head of the actin molecule. 
E)  Tropomyosin has ATPase activity and interacts with the actin.

Question 2

Which represents a similarity between fast- and slow-twitch muscle fibers?

Accepted Answer

A)  Number of mitochondria 
B)  Amount of myoglobin 
C)  Activity of glycolytic enzymes 
D)  Number of neuromuscular junctions 
E)  Number of blood vessels 
A)  Number of mitochondria 
B)  Amount of myoglobin 
C)  Activity of glycolytic enzymes 
D)  Number of neuromuscular junctions 
E)  Number of blood vessels

Question 3

Which statement about myosin is true?

Accepted Answer

A)  A thick filament consists of actin and myosin. 
B)  Myosin filaments consist of linear troponin molecules attached to tropomyosin heads. 
C)  Troponin binds to the head of the myosin molecule. 
D)  Myosin activity is regulated by tropomyosin,which binds to myosin tails. 
E)  Myosin heads have ATPase activity and interact with actin. 
A)  A thick filament consists of actin and myosin. 
B)  Myosin filaments consist of linear troponin molecules attached to tropomyosin heads. 
C)  Troponin binds to the head of the myosin molecule. 
D)  Myosin activity is regulated by tropomyosin,which binds to myosin tails. 
E)  Myosin heads have ATPase activity and interact with actin.

Question 4

A biologist studying the electric organ in a fish species observes very little actin or myosin in the cells,even though they are known to have evolved from muscle cells.Several hypotheses have been proposed to account for this observation.Which hypothesis is the most probable?

Accepted Answer

A)  The genes for actin and myosin have been lost from the chromosomes in these cells. 
B)  The cells actively degrade actin and myosin at a higher rate than muscle cells do. 
C)  The cells transport actin and myosin out into the extracellular space. 
D)  The genes for actin and myosin are expressed at a much lower level than they are in muscle cells. 
E)  Actin and myosin are modified by the cells to an extent that they lose their identification as actin or myosin. 
A)  The genes for actin and myosin have been lost from the chromosomes in these cells. 
B)  The cells actively degrade actin and myosin at a higher rate than muscle cells do. 
C)  The cells transport actin and myosin out into the extracellular space. 
D)  The genes for actin and myosin are expressed at a much lower level than they are in muscle cells. 
E)  Actin and myosin are modified by the cells to an extent that they lose their identification as actin or myosin.

Question 5

Protein conformational change is essential during the molecular sequence of events of muscle contraction.If the muscle begins in a relaxed mode and is stimulated to contract by a nerve impulse,what is the correct order of protein conformational changes that will follow?

Accepted Answer

A)  Myosin,troponin,tropomyosin 
B)  Troponin,tropomyosin,myosin 
C)  Tropomyosin,myosin,troponin 
D)  Myosin,tropomyosin,troponin 
E)  Tropomyosin,troponin,myosin 
A)  Myosin,troponin,tropomyosin 
B)  Troponin,tropomyosin,myosin 
C)  Tropomyosin,myosin,troponin 
D)  Myosin,tropomyosin,troponin 
E)  Tropomyosin,troponin,myosin

Question 6

Which type of muscle cell is shown in the image below?

Accepted Answer

A)  Skeletal 
B)  Cardiac 
C)  Smooth 
D)  Insect flight muscle 
E)  Both a and d 
A)  Skeletal 
B)  Cardiac 
C)  Smooth 
D)  Insect flight muscle 
E)  Both a and d

Question 7

Using mice,a biologist studying the cycle of protein interactions in muscle contraction has induced a mutation in one of the genes encoding proteins involved in this cycle.She finds that the muscle fibers expressing this mutation are not able to contract.Upon further investigation,she finds that calcium release into the sarcoplasm is normal,and calcium binding to protein filaments is normal.Which hypothesis could explain this mutation?

Accepted Answer

A)  The mutation occurs at the site on actin where myosin binds. 
B)  The mutation occurs in a region of tropomyosin that undergoes conformational change to expose the myosin-binding site on actin. 
C)  The mutation occurs in the myosin tail region,preventing titin binding to myosin. 
D)  The mutation occurs in myosin and prevents release of inorganic phosphate from the ATP binding site. 
E)  All of the above 
A)  The mutation occurs at the site on actin where myosin binds. 
B)  The mutation occurs in a region of tropomyosin that undergoes conformational change to expose the myosin-binding site on actin. 
C)  The mutation occurs in the myosin tail region,preventing titin binding to myosin. 
D)  The mutation occurs in myosin and prevents release of inorganic phosphate from the ATP binding site. 
E)  All of the above

Question 8

Fast-twitch skeletal muscle fibers,called white muscle,are characterized by

Accepted Answer

A)  a high concentration of myoglobin. 
B)  abundant mitochondria. 
C)  the rapid development of high tension. 
D)  the ability to sustain activity for a long time. 
E)  a higher oxygen requirement than that of slow-twitch fibers. 
A)  a high concentration of myoglobin. 
B)  abundant mitochondria. 
C)  the rapid development of high tension. 
D)  the ability to sustain activity for a long time. 
E)  a higher oxygen requirement than that of slow-twitch fibers.

Question 9

The animals listed in the table below were grouped together because they share certain characteristics.What would be the appropriate heading for this grouping?

Accepted Answer

A)  Marine Animals 
B)  Vertebrates 
C)  Animals with Hydrostatic Skeletons 
D)  Animals with Exoskeletons 
E)  Animals Lacking Skeletons 
A)  Marine Animals 
B)  Vertebrates 
C)  Animals with Hydrostatic Skeletons 
D)  Animals with Exoskeletons 
E)  Animals Lacking Skeletons

Question 10

Refer to the diagram below.Based on the diagram,which sequence represents the stages of muscle contraction in the correct order?

Accepted Answer

A)  A,B,C,D,E,F 
B)  A,F,E,D,C,B 
C)  A,C,D,E,F,B 
D)  A,C,B,F,E,D 
E)  A,D,C,B,F,E 
A)  A,B,C,D,E,F 
B)  A,F,E,D,C,B 
C)  A,C,D,E,F,B 
D)  A,C,B,F,E,D 
E)  A,D,C,B,F,E

Question 11

Which structure uses smooth muscle contractions to function?

Accepted Answer

A)  Heart 
B)  Tongue 
C)  Eyelid 
D)  Knee 
E)  Bladder 
A)  Heart 
B)  Tongue 
C)  Eyelid 
D)  Knee 
E)  Bladder

Question 12

An individual sarcomere unit consists primarily of

Accepted Answer

A)  a stack of actin fibers. 
B)  a stack of myosin units. 
C)  overlapping actin and membrane. 
D)  overlapping myosin and membrane. 
E)  overlapping actin and myosin filaments. 
A)  a stack of actin fibers. 
B)  a stack of myosin units. 
C)  overlapping actin and membrane. 
D)  overlapping myosin and membrane. 
E)  overlapping actin and myosin filaments.

Question 13

A grasshopper is capable of jumping extremely long distances.What is the most likely explanation of the mechanism that makes this possible?

Accepted Answer

A)  The grasshopper's leg consists of an exoskeleton lever powered by two muscles that contract and relax in opposition. 
B)  A hydrostatic skeleton within the grasshopper's legs allows muscles to push against body fluids. 
C)  An antagonistic pair of muscles pull in opposite directions around a joint connecting two pieces of cartilage in the grasshopper's leg. 
D)  There are two muscles within the leg portion of the grasshopper's exoskeleton,one that pushes and one that pulls. 
E)  Hydrostatic pressure that builds up inside the grasshopper's leg is released rapidly. 
A)  The grasshopper's leg consists of an exoskeleton lever powered by two muscles that contract and relax in opposition. 
B)  A hydrostatic skeleton within the grasshopper's legs allows muscles to push against body fluids. 
C)  An antagonistic pair of muscles pull in opposite directions around a joint connecting two pieces of cartilage in the grasshopper's leg. 
D)  There are two muscles within the leg portion of the grasshopper's exoskeleton,one that pushes and one that pulls. 
E)  Hydrostatic pressure that builds up inside the grasshopper's leg is released rapidly.

Question 14

Refer to the graph below showing the capacity of three systems that provide ATP for muscle contraction in humans.Based on the diagram,which statement is true?

Accepted Answer

A)  The system of curve A metabolizes carbohydrates to pyruvate and lactate. 
B)  The system of curve B comes on line within seconds but lacks sustained efficiency. 
C)  The system of curve B uses ATP produced by oxidative metabolism. 
D)  The system of curve C uses preformed ATP and creatine phosphate. 
E)  The system of curve C enables fast-twitch fibers to generate force quickly. 
A)  The system of curve A metabolizes carbohydrates to pyruvate and lactate. 
B)  The system of curve B comes on line within seconds but lacks sustained efficiency. 
C)  The system of curve B uses ATP produced by oxidative metabolism. 
D)  The system of curve C uses preformed ATP and creatine phosphate. 
E)  The system of curve C enables fast-twitch fibers to generate force quickly.

Question 15

Salmon returning to spawn in their native stream require extreme endurance for the journey.An examination of the muscles used to perform this activity would show that they

Accepted Answer

A)  have low reserves of glycogen (metabolic fuel). 
B)  have high levels of ATPase activity. 
C)  are poorly supplied with blood vessels. 
D)  have few mitochondria. 
E)  have high levels of myoglobin. 
A)  have low reserves of glycogen (metabolic fuel). 
B)  have high levels of ATPase activity. 
C)  are poorly supplied with blood vessels. 
D)  have few mitochondria. 
E)  have high levels of myoglobin.

Exam 33: Muscle and Movement

Which statement about actin is true?

Which represents a similarity between fast- and slow-twitch muscle fibers?

Which statement about myosin is true?

A biologist studying the electric organ in a fish species observes very little actin or myosin in the cells,even though they are known to have evolved from muscle cells.Several hypotheses have been proposed to account for this observation.Which hypothesis is the most probable?

Protein conformational change is essential during the molecular sequence of events of muscle contraction.If the muscle begins in a relaxed mode and is stimulated to contract by a nerve impulse,what is the correct order of protein conformational changes that will follow?

Which type of muscle cell is shown in the image below?

Fast-twitch skeletal muscle fibers,called white muscle,are characterized by

The animals listed in the table below were grouped together because they share certain characteristics.What would be the appropriate heading for this grouping?

Refer to the diagram below.Based on the diagram,which sequence represents the stages of muscle contraction in the correct order?

Which structure uses smooth muscle contractions to function?

An individual sarcomere unit consists primarily of

A grasshopper is capable of jumping extremely long distances.What is the most likely explanation of the mechanism that makes this possible?

Refer to the graph below showing the capacity of three systems that provide ATP for muscle contraction in humans.Based on the diagram,which statement is true?

Salmon returning to spawn in their native stream require extreme endurance for the journey.An examination of the muscles used to perform this activity would show that they

Introduction

The Chemistry and Energy of Life

Nucleic Acids, Proteins, and Enzymes

Cells: the Working Units of Life

Cell Membranes and Signaling

Pathways That Harvest and Store Chemical Energy

The Cell Cycle and Cell Division

Inheritance, Genes, and Chromosomes

DNA and Its Role in Heredity

From Dna to Protein: Gene Expression

Regulation of Gene Expression

Genomes

Biotechnology

Genes, Development, and Evolution

Processes of Evolution

Reconstructing and Using Phylogenies

Speciation

The History of Life on Earth

Bacteria, Archaea, and Viruses

The Origin and Diversification of Eukaryotes

The Evolution of Plants

The Evolution and Diversity of Fungi

Animal Origins and Diversity

The Plant Body

Plant Nutrition and Transport

Plant Growth and Development

Reproduction of Flowering Plants

Plants in the Environment

Fundamentals of Animal Function

Nutrition and Digestion

Breathing

Circulation

Neurons, Sense Organs, and Nervous Systems

Nervous and Endocrine Control

Water and Salts: Excretion

Animal Reproduction

Animal Development

Immunology: Animal Defense Systems

Animal Behavior

The Distribution of Earths Ecological Systems

Populations

Ecological and Evolutionary Consequences of Interactions Within and Among Species

Ecological Communities

The Global Ecosystem

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