Question 1

Smooth muscle differs from both cardiac and skeletal muscle in that

Accepted Answer

A)  it can act as a pacemaker for rhythmic contractions. 
B)  contractions of smooth muscle are not due to Ca2+ influx into the sarcoplasm. 
C)  neighboring cells in smooth muscle are electrically coupled by gap junctions. 
D)  neighboring cells in smooth muscle are tightly connected by intercalated discs. 
E)  its actin and myosin show no repeating pattern of arrangement when viewed under a microscope. 
A)  it can act as a pacemaker for rhythmic contractions. 
B)  contractions of smooth muscle are not due to Ca2+ influx into the sarcoplasm. 
C)  neighboring cells in smooth muscle are electrically coupled by gap junctions. 
D)  neighboring cells in smooth muscle are tightly connected by intercalated discs. 
E)  its actin and myosin show no repeating pattern of arrangement when viewed under a microscope.

Question 2

The figure below shows an electron micrograph of a portion of one insect flight muscle cell.Identify the structures labeled A and B.

Accepted Answer

A)  A = actin and myosin filaments;B = gap junctions 
B)  A = T tubules;B = sarcoplasm 
C)  A = actin and myosin filaments;B = mitochondria 
D)  A = T tubules;B = mitochondria 
E)  A = sarcoplasm;B = gap junctions 
A)  A = actin and myosin filaments;B = gap junctions 
B)  A = T tubules;B = sarcoplasm 
C)  A = actin and myosin filaments;B = mitochondria 
D)  A = T tubules;B = mitochondria 
E)  A = sarcoplasm;B = gap junctions

Question 3

Which two animals have the same type of skeletal system?

Accepted Answer

A)  Whale and earthworm 
B)  Squid and crab 
C)  Trout and moth 
D)  Ant and lobster 
E)  Hawk and dragonfly 
A)  Whale and earthworm 
B)  Squid and crab 
C)  Trout and moth 
D)  Ant and lobster 
E)  Hawk and dragonfly

Question 4

Compared to the legs of sedentary people,the legs of cross-country skiers and long-distance runners are likely to have

Accepted Answer

A)  almost all slow-twitch fibers. 
B)  almost all fast-twitch fibers. 
C)  about the same number of slow-twitch and fast-twitch fibers. 
D)  more slow-twitch fibers. 
E)  more fast-twitch fibers. 
A)  almost all slow-twitch fibers. 
B)  almost all fast-twitch fibers. 
C)  about the same number of slow-twitch and fast-twitch fibers. 
D)  more slow-twitch fibers. 
E)  more fast-twitch fibers.

Question 5

Bricklayers occasionally need to carry stacks of bricks from their truck to the work site;this is a heavy load,but it is only carried a short distance.An examination of the muscles used to perform this work would show that they

Accepted Answer

A)  have substantial reserves of fuel. 
B)  have low levels of ATPase activity. 
C)  are well-supplied with blood vessels. 
D)  have relatively few mitochondria. 
E)  develop tension slowly. 
A)  have substantial reserves of fuel. 
B)  have low levels of ATPase activity. 
C)  are well-supplied with blood vessels. 
D)  have relatively few mitochondria. 
E)  develop tension slowly.

Question 6

A chemical compound has been used as a rodent poison for many years although scientists do not know specifically how it causes death.Recently the compound was shown to bind to the dihydropyridine (DHP)receptor.What would be the best question to ask next in continued research about the mechanism of this compound?

Accepted Answer

A)  Does the compound interfere with depolarization of T tubules? 
B)  Does the compound interfere with the binding of calcium to troponin? 
C)  Does the compound inhibit an action potential from developing in the muscle cell membrane and traveling down the T tubules in response to a nerve impulse? 
D)  Does the compound prevent calcium release from the sarcoplasmic reticulum into the sarcoplasm following a nerve impulse? 
E)  Does the compound prevent cross-bridge release between actin and myosin to allow a new cycle of contraction? 
A)  Does the compound interfere with depolarization of T tubules? 
B)  Does the compound interfere with the binding of calcium to troponin? 
C)  Does the compound inhibit an action potential from developing in the muscle cell membrane and traveling down the T tubules in response to a nerve impulse? 
D)  Does the compound prevent calcium release from the sarcoplasmic reticulum into the sarcoplasm following a nerve impulse? 
E)  Does the compound prevent cross-bridge release between actin and myosin to allow a new cycle of contraction?

Question 7

Regarding skeletal,smooth,and cardiac muscle cells,which structure(s)is/are present in all three types?

Accepted Answer

A)  Sarcomere 
B)  Sarcoplasmic reticulum 
C)  Gap junctions 
D)  Intercalated discs 
E)  Striations 
A)  Sarcomere 
B)  Sarcoplasmic reticulum 
C)  Gap junctions 
D)  Intercalated discs 
E)  Striations

Question 8

Student 1 states that butterflies have exoskeletons,while student 2 states that before metamorphosis,butterflies exist in caterpillar form and have no skeleton.Which student is correct?

Accepted Answer

A)  Both students are correct. 
B)  Neither student is correct because butterflies have no skeletons and caterpillars have hydrostatic skeletons. 
C)  Student 1 is correct;student 2 is incorrect because caterpillars have endoskeletons. 
D)  Student 2 is correct;student 1 is incorrect because butterflies have no skeletons. 
E)  Student 1 is correct;student 2 is incorrect because caterpillars have hydrostatic skeletons. 
A)  Both students are correct. 
B)  Neither student is correct because butterflies have no skeletons and caterpillars have hydrostatic skeletons. 
C)  Student 1 is correct;student 2 is incorrect because caterpillars have endoskeletons. 
D)  Student 2 is correct;student 1 is incorrect because butterflies have no skeletons. 
E)  Student 1 is correct;student 2 is incorrect because caterpillars have hydrostatic skeletons.

Question 9

When troponin binds calcium,

Accepted Answer

A)  it changes conformation,twisting tropomyosin and exposing the actin-myosin binding site. 
B)  ion channels open and sodium rushes into the muscle cells. 
C)  it allows tropomyosin to bind actin. 
D)  it changes conformation,exposing the ATP binding site and allowing the actin-myosin bond to break. 
E)  ATP binds to the myosin head,allowing myosin to attach to actin. 
A)  it changes conformation,twisting tropomyosin and exposing the actin-myosin binding site. 
B)  ion channels open and sodium rushes into the muscle cells. 
C)  it allows tropomyosin to bind actin. 
D)  it changes conformation,exposing the ATP binding site and allowing the actin-myosin bond to break. 
E)  ATP binds to the myosin head,allowing myosin to attach to actin.

Question 10

Slow-twitch fibers

Accepted Answer

A)  are also called oxidative muscle. 
B)  are also called red muscle. 
C)  are well supplied with mitochondria. 
D)  contain the oxygen-binding protein myoglobin. 
E)  All of the above 
A)  are also called oxidative muscle. 
B)  are also called red muscle. 
C)  are well supplied with mitochondria. 
D)  contain the oxygen-binding protein myoglobin. 
E)  All of the above

Question 11

What allows muscle fibers to shorten during contraction?

Accepted Answer

A)  Individual protein filaments contract. 
B)  Cross-bridges between filaments break. 
C)  Arrays of filaments slide against each other. 
D)  Protein filaments coil more tightly. 
E)  Subunits of protein polymers detach. 
A)  Individual protein filaments contract. 
B)  Cross-bridges between filaments break. 
C)  Arrays of filaments slide against each other. 
D)  Protein filaments coil more tightly. 
E)  Subunits of protein polymers detach.

Question 12

Which statement about fast-twitch and slow-twitch fibers is false?

Accepted Answer

A)  Athletes in different sports show different percentages of slow-twitch muscle fibers. 
B)  Differences in the amount of myoglobin and number of mitochondria contribute to the differences in the color of fibers. 
C)  A single muscle may contain fast- and slow-twitch fibers. 
D)  Fast-twitch fibers fatigue slowly. 
E)  The proportion of fast-twitch and slow-twitch fibers in muscle can be altered using different types of athletic training. 
A)  Athletes in different sports show different percentages of slow-twitch muscle fibers. 
B)  Differences in the amount of myoglobin and number of mitochondria contribute to the differences in the color of fibers. 
C)  A single muscle may contain fast- and slow-twitch fibers. 
D)  Fast-twitch fibers fatigue slowly. 
E)  The proportion of fast-twitch and slow-twitch fibers in muscle can be altered using different types of athletic training.

Question 13

Refer to the figure below.Which statement accurately describes the H zone and I bands of a sarcomere?

Accepted Answer

A)  The H zone and I bands are regions of the sarcomere that appear light under the microscope because they both represent areas where myosin but not actin filaments are present. 
B)  The H zone and I bands are the only regions of the sarcomere that do not shorten or lengthen as the sarcomere contracts. 
C)  A shortening of the H zone is always accompanied by a shortening of the I bands,and a lengthening of the H zone is always accompanied by a lengthening of the I bands. 
D)  Stimulation by an action potential results in a lengthening of the H zone but a shortening of the I bands. 
E)  The H zone,but not the I bands,change in width during contraction of the sarcomere. 
A)  The H zone and I bands are regions of the sarcomere that appear light under the microscope because they both represent areas where myosin but not actin filaments are present. 
B)  The H zone and I bands are the only regions of the sarcomere that do not shorten or lengthen as the sarcomere contracts. 
C)  A shortening of the H zone is always accompanied by a shortening of the I bands,and a lengthening of the H zone is always accompanied by a lengthening of the I bands. 
D)  Stimulation by an action potential results in a lengthening of the H zone but a shortening of the I bands. 
E)  The H zone,but not the I bands,change in width during contraction of the sarcomere.

Question 14

Which two animals have different types of skeletal systems?

Accepted Answer

A)  Turtle and crab 
B)  Flounder and sparrow 
C)  House fly and crayfish 
D)  Shark and frog 
E)  Spider and cricket 
A)  Turtle and crab 
B)  Flounder and sparrow 
C)  House fly and crayfish 
D)  Shark and frog 
E)  Spider and cricket

Question 15

How are endoskeletons similar to exoskeletons?

Accepted Answer

A)  Both consist of the same biomaterials. 
B)  Both use antagonistic pairs of muscles to cause motion. 
C)  Both cover and surround all of the soft tissues of an organism. 
D)  Both represent inert,nonliving tissue. 
E)  Both use muscles pushing against body fluids to cause motion. 
A)  Both consist of the same biomaterials. 
B)  Both use antagonistic pairs of muscles to cause motion. 
C)  Both cover and surround all of the soft tissues of an organism. 
D)  Both represent inert,nonliving tissue. 
E)  Both use muscles pushing against body fluids to cause motion.

Question 16

A biologist is looking at human muscle fibers under the microscope.Which criterion should the biologist use to distinguish between skeletal and cardiac muscle fibers?

Accepted Answer

A)  Presence or absence of T tubules 
B)  Presence or absence of regular arrays of thick and thin filaments 
C)  Number of mitochondria 
D)  Number of cell nuclei 
E)  Presence or absence of a sarcoplasmic reticulum 
A)  Presence or absence of T tubules 
B)  Presence or absence of regular arrays of thick and thin filaments 
C)  Number of mitochondria 
D)  Number of cell nuclei 
E)  Presence or absence of a sarcoplasmic reticulum

Question 17

Which remains constant as a skeletal muscle relaxes following contraction?

Accepted Answer

A)  A band 
B)  H zone 
C)  I band 
D)  Distance between Z lines 
E)  Overall width of a sarcomere 
A)  A band 
B)  H zone 
C)  I band 
D)  Distance between Z lines 
E)  Overall width of a sarcomere

Question 18

Starting with the arrival of an action potential at the neuromuscular junction,which is the correct order of events?

Accepted Answer

A)  Calcium is released from the sarcoplasmic reticulum,an action potential travels down the T tubule,depolarization spreads through the T tubule,and myosin binds actin. 
B)  An action potential travels down the T tubule,depolarization spreads through the T tubule,calcium is released from the sarcoplasmic reticulum,and myosin binds actin. 
C)  An action potential travels down the T tubule,depolarization spreads through the T tubule,calcium is taken up by the sarcoplasmic reticulum,and myosin binds actin. 
D)  An action potential travels down the T tubule,depolarization spreads through the T tubule,ATP binds to myosin,and myosin binds actin. 
E)  The T tubule is depolarized,calcium is released from the sarcoplasmic reticulum,an action potential is created in the muscle cell,and myosin binds actin. 
A)  Calcium is released from the sarcoplasmic reticulum,an action potential travels down the T tubule,depolarization spreads through the T tubule,and myosin binds actin. 
B)  An action potential travels down the T tubule,depolarization spreads through the T tubule,calcium is released from the sarcoplasmic reticulum,and myosin binds actin. 
C)  An action potential travels down the T tubule,depolarization spreads through the T tubule,calcium is taken up by the sarcoplasmic reticulum,and myosin binds actin. 
D)  An action potential travels down the T tubule,depolarization spreads through the T tubule,ATP binds to myosin,and myosin binds actin. 
E)  The T tubule is depolarized,calcium is released from the sarcoplasmic reticulum,an action potential is created in the muscle cell,and myosin binds actin.

Question 19

How does tropomyosin control muscle contraction?

Accepted Answer

A)  It provides a bridge between actin and myosin. 
B)  It provides a site where ATP can be utilized. 
C)  Changes in its position expose myosin-binding sites on actin filaments. 
D)  It transmits electric charge to the filaments. 
E)  Changes in its shape cause membrane channels to open. 
A)  It provides a bridge between actin and myosin. 
B)  It provides a site where ATP can be utilized. 
C)  Changes in its position expose myosin-binding sites on actin filaments. 
D)  It transmits electric charge to the filaments. 
E)  Changes in its shape cause membrane channels to open.

Question 20

If the slow-twitch muscle fibers of a marathon runner,weight lifter,and triathlon competitor (5K run,1K swim,10K bicycle ride)were compared,which would represent the correct order of the percentage of slow-twitch muscle fibers observed in their bodies (from the athlete with the highest percentage to the athlete with the lowest)?

Accepted Answer

A)  Marathon runner,triathlete,weight lifter 
B)  Weight lifter,marathon runner,triathlete 
C)  Triathlete,marathon runner,weight lifter 
D)  Triathlete,weight lifter,marathon runner 
E)  Marathon runner,weight lifter,triathlete 
A)  Marathon runner,triathlete,weight lifter 
B)  Weight lifter,marathon runner,triathlete 
C)  Triathlete,marathon runner,weight lifter 
D)  Triathlete,weight lifter,marathon runner 
E)  Marathon runner,weight lifter,triathlete

Exam 33: Muscle and Movement

Smooth muscle differs from both cardiac and skeletal muscle in that

The figure below shows an electron micrograph of a portion of one insect flight muscle cell.Identify the structures labeled A and B.

Which two animals have the same type of skeletal system?

Compared to the legs of sedentary people,the legs of cross-country skiers and long-distance runners are likely to have

Bricklayers occasionally need to carry stacks of bricks from their truck to the work site;this is a heavy load,but it is only carried a short distance.An examination of the muscles used to perform this work would show that they

Regarding skeletal,smooth,and cardiac muscle cells,which structure(s)is/are present in all three types?

Student 1 states that butterflies have exoskeletons,while student 2 states that before metamorphosis,butterflies exist in caterpillar form and have no skeleton.Which student is correct?

When troponin binds calcium,

Slow-twitch fibers

What allows muscle fibers to shorten during contraction?

Which statement about fast-twitch and slow-twitch fibers is false?

Refer to the figure below.Which statement accurately describes the H zone and I bands of a sarcomere?

Which two animals have different types of skeletal systems?

How are endoskeletons similar to exoskeletons?

A biologist is looking at human muscle fibers under the microscope.Which criterion should the biologist use to distinguish between skeletal and cardiac muscle fibers?

Which remains constant as a skeletal muscle relaxes following contraction?

Starting with the arrival of an action potential at the neuromuscular junction,which is the correct order of events?

How does tropomyosin control muscle contraction?

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

Filters