Question 1

What causes rigor mortis?

Accepted Answer

A)  exhaustion of Ca2+ from the sarcoplasmic reticulum 
B)  lack of ATP in dead tissue 
C)  lack of acetylcholine (ACh) in dead tissue 
D)  cessation of action potentials after death 
A)  exhaustion of Ca2+ from the sarcoplasmic reticulum 
B)  lack of ATP in dead tissue 
C)  lack of acetylcholine (ACh) in dead tissue 
D)  cessation of action potentials after death B

Question 2

Motor neurons release the neurotransmitter acetylcholine (ACh), and acetylcholinesterase degrades ACh in the synapse. If a neurophysiologist applies onchidal (a naturally occurring acetylcholinesterase inhibitor produced by the mollusk Onchidella binneyi) to a synapse, what would you expect to happen?

Accepted Answer

A)  paralysis of muscle tissue 
B)  gradual loss of resting potential 
C)  convulsions due to constant muscle stimulation 
D)  decrease in the frequency of action potentials 
E)  no effect 
A)  paralysis of muscle tissue 
B)  gradual loss of resting potential 
C)  convulsions due to constant muscle stimulation 
D)  decrease in the frequency of action potentials 
E)  no effect C

Question 3

Sections of actin filaments that are NOT overlapping with myosin are indicated by which letter in the figure?

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  D 
E)  E 
A)  A 
B)  B 
C)  C 
D)  D 
E)  E A

Question 4

Why are the muscles used for movement in insects often pennate?

Accepted Answer

A)  The limited space within insect exoskeletons requires muscle that generates high force without changing size significantly. 
B)  Insects molt to grow their skeleton. 
C)  The internal muscle includes both flexor and extensor muscles. 
D)  Insects require muscle that generates large length changes to compensate for lack of joints in the skeleton. 
A)  The limited space within insect exoskeletons requires muscle that generates high force without changing size significantly. 
B)  Insects molt to grow their skeleton. 
C)  The internal muscle includes both flexor and extensor muscles. 
D)  Insects require muscle that generates large length changes to compensate for lack of joints in the skeleton.

Question 5

What is the effect of the release of norepinephrine by the sympathetic nervous system?

Accepted Answer

A)  Smooth muscle and cardiac muscle relax. 
B)  Smooth muscle and cardiac muscle are activated and increase the force of their muscle contractions. 
C)  Smooth muscle relaxes, while cardiac muscle has increased contractile force. 
D)  Cardiac muscle relaxes, while smooth muscle is stimulated to increase activity. 
A)  Smooth muscle and cardiac muscle relax. 
B)  Smooth muscle and cardiac muscle are activated and increase the force of their muscle contractions. 
C)  Smooth muscle relaxes, while cardiac muscle has increased contractile force. 
D)  Cardiac muscle relaxes, while smooth muscle is stimulated to increase activity.

Question 6

What would happen to people exposed to a chemical warfare agent that blocked acetylcholine from binding to muscle receptors?

Accepted Answer

A)  Action potentials would be continuously generated, causing convulsive muscle contractions. 
B)  Muscle contractions would be prevented, causing paralysis. 
C)  Muscle contractions could still occur, but relaxation of the muscle would be impaired. 
D)  Action potentials would be continuously generated, causing convulsive muscle contractions; muscle contractions would then be prevented, causing paralysis. 
A)  Action potentials would be continuously generated, causing convulsive muscle contractions. 
B)  Muscle contractions would be prevented, causing paralysis. 
C)  Muscle contractions could still occur, but relaxation of the muscle would be impaired. 
D)  Action potentials would be continuously generated, causing convulsive muscle contractions; muscle contractions would then be prevented, causing paralysis.

Question 7

Which of the following is the correct sequence that describes the excitation and contraction of a skeletal muscle fiber?
1) Tropomyosin shifts and unblocks the cross-bridge binding sites.
2) Calcium is released and binds to the troponin complex.
3) The sarcoplasmic reticulum is depolarized when a wave of depolarization moves from the neuromuscular junction into the cell's interior by way of the transverse tubules.
4) The thin filaments are ratcheted across the thick filaments by the heads of the myosin molecules using energy from ATP.
5) An action potential in a motor neuron causes the axon to release acetylcholine, which depolarizes the muscle cell membrane at the neuromuscular junction.

Accepted Answer

A)  1 → 2 → 3 → 4 → 5 
B)  2 → 1 → 3 → 5 → 4 
C)  3 → 4 → 2 → 1 → 5 
D)  5 → 3 → 1 → 2 → 4 
E)  5 → 3 → 2 → 1 → 4 
A)  1 → 2 → 3 → 4 → 5 
B)  2 → 1 → 3 → 5 → 4 
C)  3 → 4 → 2 → 1 → 5 
D)  5 → 3 → 1 → 2 → 4 
E)  5 → 3 → 2 → 1 → 4

Question 8

Which muscle type(s) is (are) involuntary?

Accepted Answer

A)  smooth muscle 
B)  cardiac muscle 
C)  skeletal muscle 
D)  smooth and cardiac muscle 
E)  cardiac and skeletal muscle 
A)  smooth muscle 
B)  cardiac muscle 
C)  skeletal muscle 
D)  smooth and cardiac muscle 
E)  cardiac and skeletal muscle

Question 9

In a relaxed skeletal muscle ________.

Accepted Answer

A)  thick and thin filaments overlap to the greatest extent possible 
B)  sarcomeres are at their shortest length 
C)  calcium is released from the sarcoplasmic reticulum 
D)  the Z lines are farthest apart 
A)  thick and thin filaments overlap to the greatest extent possible 
B)  sarcomeres are at their shortest length 
C)  calcium is released from the sarcoplasmic reticulum 
D)  the Z lines are farthest apart

Question 10

Why do horses tend to move at only limited ranges of speeds?

Accepted Answer

A)  They are only capable of one speed for each of their gaits-walk, trot, gallop. 
B)  Walking is the most energetically costly form of locomotion for horses. 
C)  Because of their size, horses have limited gaits and, therefore, limited speeds. 
D)  They locomote using the most energy-efficient combinations of gait and speed. 
A)  They are only capable of one speed for each of their gaits-walk, trot, gallop. 
B)  Walking is the most energetically costly form of locomotion for horses. 
C)  Because of their size, horses have limited gaits and, therefore, limited speeds. 
D)  They locomote using the most energy-efficient combinations of gait and speed.

Question 11

R. McNeill Alexander demonstrated that tendons improve the efficiency of running by ________.

Accepted Answer

A)  connecting bones to bones and keeping the skeleton intact 
B)  storing and releasing energy like a spring with each step 
C)  generating force to relengthen muscle once it relaxes 
D)  acting like a stiff rod and communicating force without stretching 
A)  connecting bones to bones and keeping the skeleton intact 
B)  storing and releasing energy like a spring with each step 
C)  generating force to relengthen muscle once it relaxes 
D)  acting like a stiff rod and communicating force without stretching

Question 12

The calcium ions released into the cytosol during excitation of skeletal muscle bind to ________.

Accepted Answer

A)  troponin complex 
B)  transverse tubules 
C)  actin 
D)  myosin 
A)  troponin complex 
B)  transverse tubules 
C)  actin 
D)  myosin

Question 13

When muscle is at rest, the myosin head is bound to ________.

Accepted Answer

A)  ATP 
B)  tropomyosin 
C)  ADP plus an associated phosphate 
D)  troponin 
E)  actin 
A)  ATP 
B)  tropomyosin 
C)  ADP plus an associated phosphate 
D)  troponin 
E)  actin

Question 14

Which muscle type(s) is (are) composed of multinucleate cells resulting from the fusion of many embryonic cells?

Accepted Answer

A)  smooth muscle 
B)  cardiac muscle 
C)  skeletal muscle 
D)  smooth and cardiac muscle 
E)  cardiac and skeletal muscle 
A)  smooth muscle 
B)  cardiac muscle 
C)  skeletal muscle 
D)  smooth and cardiac muscle 
E)  cardiac and skeletal muscle

Question 15

The marathon is a 26.2-mile-long, endurance running race. Successful marathon runners will benefit from having leg muscles with a relatively high amount of ________.

Accepted Answer

A)  slow muscle fibers 
B)  intermediate muscle fibers 
C)  smooth muscle fibers 
D)  cardiac muscle fibers 
E)  fast muscle fibers 
A)  slow muscle fibers 
B)  intermediate muscle fibers 
C)  smooth muscle fibers 
D)  cardiac muscle fibers 
E)  fast muscle fibers

Question 16

Which forces are most important during terrestrial locomotion?

Accepted Answer

A)  buoyancy and drag forces 
B)  lift and drag forces 
C)  gravity and inertial forces 
D)  inertial forces and buoyancy 
E)  gravity and drag forces 
A)  buoyancy and drag forces 
B)  lift and drag forces 
C)  gravity and inertial forces 
D)  inertial forces and buoyancy 
E)  gravity and drag forces

Question 17

Cardiac muscle cells are both ________.

Accepted Answer

A)  striated and interconnected by intercalated disks 
B)  striated and operate independently of other cardiac cells 
C)  smooth and under voluntary control 
D)  striated and under voluntary control 
E)  smooth and under involuntary control 
A)  striated and interconnected by intercalated disks 
B)  striated and operate independently of other cardiac cells 
C)  smooth and under voluntary control 
D)  striated and under voluntary control 
E)  smooth and under involuntary control

Question 18

Chitin is a major component of the ________.

Accepted Answer

A)  skeleton of mammals 
B)  hydrostatic skeletons of earthworms 
C)  exoskeleton of insects 
D)  body hairs of mammals 
E)  skeleton in birds 
A)  skeleton of mammals 
B)  hydrostatic skeletons of earthworms 
C)  exoskeleton of insects 
D)  body hairs of mammals 
E)  skeleton in birds

Question 19

During the contraction of a vertebrate skeletal muscle fiber, calcium ions ________.

Accepted Answer

A)  break cross-bridges by acting as a cofactor in the hydrolysis of ATP 
B)  bind with troponin, causing its shape to change so that the myosin-binding sites on actin are exposed 
C)  transmit action potentials from the motor neuron to the muscle fiber 
D)  spread action potentials through the T tubules 
E)  reestablish the polarization of the plasma membrane following an action potential 
A)  break cross-bridges by acting as a cofactor in the hydrolysis of ATP 
B)  bind with troponin, causing its shape to change so that the myosin-binding sites on actin are exposed 
C)  transmit action potentials from the motor neuron to the muscle fiber 
D)  spread action potentials through the T tubules 
E)  reestablish the polarization of the plasma membrane following an action potential

Question 20

A patient is hospitalized with muscle spasms caused by failure of back muscles to relax after contraction. Which of the following would be most likely to help?

Accepted Answer

A)  injecting calcium into the muscle cell, because it is not being released from the sarcoplasmic reticulum 
B)  inducing tropomyosin-troponin complex to block the myosin binding sites on actin 
C)  increasing the amount of acetylcholine at the synapses between motor neurons and muscle cells 
D)  depolarizing the motor neurons to send an action potential to the muscle cells 
A)  injecting calcium into the muscle cell, because it is not being released from the sarcoplasmic reticulum 
B)  inducing tropomyosin-troponin complex to block the myosin binding sites on actin 
C)  increasing the amount of acetylcholine at the synapses between motor neurons and muscle cells 
D)  depolarizing the motor neurons to send an action potential to the muscle cells

Exam 45: Animal Movement

What causes rigor mortis?

Sections of actin filaments that are NOT overlapping with myosin are indicated by which letter in the figure?

Why are the muscles used for movement in insects often pennate?

What is the effect of the release of norepinephrine by the sympathetic nervous system?

What would happen to people exposed to a chemical warfare agent that blocked acetylcholine from binding to muscle receptors?

Which muscle type(s) is (are) involuntary?

In a relaxed skeletal muscle ________.

Why do horses tend to move at only limited ranges of speeds?

R. McNeill Alexander demonstrated that tendons improve the efficiency of running by ________.

The calcium ions released into the cytosol during excitation of skeletal muscle bind to ________.

When muscle is at rest, the myosin head is bound to ________.

Which muscle type(s) is (are) composed of multinucleate cells resulting from the fusion of many embryonic cells?

The marathon is a 26.2-mile-long, endurance running race. Successful marathon runners will benefit from having leg muscles with a relatively high amount of ________.

Which forces are most important during terrestrial locomotion?

Cardiac muscle cells are both ________.

Chitin is a major component of the ________.

During the contraction of a vertebrate skeletal muscle fiber, calcium ions ________.

A patient is hospitalized with muscle spasms caused by failure of back muscles to relax after contraction. Which of the following would be most likely to help?

Biology and the Tree of Life

Water and Carbon: the Chemical Basis of Life

Protein Structure and Function

Nucleic Acids and the Rna World

An Introduction to Carbohydrates

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Lipids, Membranes, and the First Cells

Inside the Cell

Energy and Enzymes: an Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

Cellcell Interactions

The Cell Cycle

Meiosis

Mendel and the Gene

Dna and the Gene: Synthesis and Repair

How Genes Work

Transcription, Rna Processing, and Translation

Control of Gene Expression in Bacteria

Control of Gene Expression in Eukaryotes

The Molecular Revolution: Biotechnology and Beyond

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Evolutionary Processes

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Phylogenies and the History of Life

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Protists

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Viruses

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Water and Sugar Transport in Plants

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Plant Sensory Systems, Signals, and Responses

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Animal Form and Function

Water and Electrolyte Balance in Animals

Animal Nutrition

Gas Exchange and Circulation

Animal Nervous Systems

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Chemical Signals in Animals

Animal Reproduction and Development

The Immune System in Animals

An Introduction to Ecology

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