Question 1

A sport such as weight lifting, which is very demanding and leads quickly to fatigue, is reliant on _______ fibers.

Accepted Answer

The answer of A sport such as weight lifting, which...

Question 2

Which of the following is not one of the systems that supplies muscles with the ATP needed for contraction?

Accepted Answer

A)  Immediate system 
B)  System that creates lactate 
C)  Glycolytic system 
D)  Oxidative system 
E)  Haversian system 
A)  Immediate system 
B)  System that creates lactate 
C)  Glycolytic system 
D)  Oxidative system 
E)  Haversian system

Question 3

The primary determinant regarding the proportion of fast- and slow-twitch fibers in a person's skeletal muscle is

Accepted Answer

A)  diet. 
B)  exercise. 
C)  genetic heritage. 
D)  age. 
E)  geographic location. 
A)  diet. 
B)  exercise. 
C)  genetic heritage. 
D)  age. 
E)  geographic location.

Question 4

Refer to the figure.   The animal shown is able to move using the circular and longitudinal musculature within each segment.In the segment labeled 1, _______, and in the segment labeled 2, _______.

Accepted Answer

A)  longitudinal muscles are contracted; circular muscles are contracted 
B)  longitudinal muscles are relaxed; circular muscles are contracted 
C)  circular muscles are contracted; circular muscles are relaxed 
D)  circular muscles are relaxed; longitudinal muscles are contracted 
E)  longitudinal muscles are contracted; circular muscles are relaxed 
A)  longitudinal muscles are contracted; circular muscles are contracted 
B)  longitudinal muscles are relaxed; circular muscles are contracted 
C)  circular muscles are contracted; circular muscles are relaxed 
D)  circular muscles are relaxed; longitudinal muscles are contracted 
E)  longitudinal muscles are contracted; circular muscles are relaxed

Question 5

When a clown at a birthday party squeezes a long balloon to twist it into a poodle or a hat, the volume of air inside the balloon stretches the balloon and extends its length and stays constant.This example is analogous to the action of muscles on the

Accepted Answer

A)  endoskeleton. 
B)  hydrostatic skeleton. 
C)  spandrel skeleton. 
D)  exoskeleton. 
E)  tendril skeleton. 
A)  endoskeleton. 
B)  hydrostatic skeleton. 
C)  spandrel skeleton. 
D)  exoskeleton. 
E)  tendril skeleton.

Question 6

Which statement about fast-twitch fibers is true?

Accepted Answer

A)  They are more common in the leg muscles of champion sprinters than in champion marathon runners. 
B)  They have more mitochondria than slow-twitch fibers in the same muscle. 
C)  They fatigue less rapidly than slow-twitch fibers do. 
D)  Their abundance is more a product of training than of genetics. 
E)  They are more common in postural muscles than in finger muscles. 
A)  They are more common in the leg muscles of champion sprinters than in champion marathon runners. 
B)  They have more mitochondria than slow-twitch fibers in the same muscle. 
C)  They fatigue less rapidly than slow-twitch fibers do. 
D)  Their abundance is more a product of training than of genetics. 
E)  They are more common in postural muscles than in finger muscles.

Question 7

Myoblasts

Accepted Answer

A)  communicate a muscle fiber's need for more O2. 
B)  lie in a ring around the muscle fibers, absorbing their metabolic waste. 
C)  are embryonic cells that fuse to form skeletal muscle fibers. 
D)  move through the muscle fibers, providing ATP where it is most needed. 
E)  are phagocytic, watching for and then attacking pathogens in the muscle fiber. 
A)  communicate a muscle fiber's need for more O2. 
B)  lie in a ring around the muscle fibers, absorbing their metabolic waste. 
C)  are embryonic cells that fuse to form skeletal muscle fibers. 
D)  move through the muscle fibers, providing ATP where it is most needed. 
E)  are phagocytic, watching for and then attacking pathogens in the muscle fiber.

Question 8

When animals die, the lack of ATP causes muscles to stiffen in rigor mortis because

Accepted Answer

A)  muscles cannot contract without ATP. 
B)  actin and myosin cannot bind without ATP. 
C)  actin and myosin cannot separate without ATP. 
D)  ATP is required for synthesis of protein filaments. 
E)  ATP forms cross-bridges between filaments. 
A)  muscles cannot contract without ATP. 
B)  actin and myosin cannot bind without ATP. 
C)  actin and myosin cannot separate without ATP. 
D)  ATP is required for synthesis of protein filaments. 
E)  ATP forms cross-bridges between filaments.

Question 9

A pair of closely related bird species includes one that migrates long distances over the course of months and another that has evolved near-flightlessness on its island home.What might you expect to find when comparing the breast muscles (used for flight) of these species?

Accepted Answer

A)  The island species would have relatively larger amounts of red muscle. 
B)  The migrant species would have relatively larger amounts of red muscle. 
C)  The migrant species would have relatively lower levels of myoglobin. 
D)  The island species would have relatively higher numbers of mitochondria in each muscle cell. 
E)  The two species would have approximately equal amounts of fast-twitch muscle fibers. 
A)  The island species would have relatively larger amounts of red muscle. 
B)  The migrant species would have relatively larger amounts of red muscle. 
C)  The migrant species would have relatively lower levels of myoglobin. 
D)  The island species would have relatively higher numbers of mitochondria in each muscle cell. 
E)  The two species would have approximately equal amounts of fast-twitch muscle fibers.

Question 10

Refer to the figure showing an earthworm.   The earthworm is able to move using its _______ skeleton and body musculature.

Accepted Answer

The answer of Refer to the figure showing an earthworm....

Question 11

In examining a fruit fly in flight, a researcher was able to determine that the stroke frequency of the wings is 221 strokes per second.Comparing this with flight in a zebra finch, the researcher found the stroke frequency of the wings in a zebra finch was _______ than that of the fruit fly.

Accepted Answer

The answer of In examining a fruit fly in flight,...

Question 12

_______ is the continuous activation of the contractile "machinery."

Accepted Answer

The answer of _______ is the continuous activation of the...

Question 13

Which feature characterizes a muscle that is fully stretched?

Accepted Answer

A)  Shortened sarcomeres 
B)  Little overlap between actin and myosin filaments 
C)  Myosin bundles pressed up against Z lines 
D)  Maximum number of cross-bridges 
E)  Production of maximum force 
A)  Shortened sarcomeres 
B)  Little overlap between actin and myosin filaments 
C)  Myosin bundles pressed up against Z lines 
D)  Maximum number of cross-bridges 
E)  Production of maximum force

Question 14

Which statement about skeletal muscle is true?

Accepted Answer

A)  The fewer muscle fibers a motor neuron innervates, the larger the forces produced by a muscle. 
B)  A single action potential stimulates multiple twitches. 
C)  Twitches sum when action potentials arrive well separated in time. 
D)  The number of motor units activated and the frequency with which the motor units fire determine the level of tension in a muscle. 
E)  Summing of twitches occurs because ATP pumps in the sarcoplasmic reticulum are unable to clear ATP from the sarcoplasm between action potentials. 
A)  The fewer muscle fibers a motor neuron innervates, the larger the forces produced by a muscle. 
B)  A single action potential stimulates multiple twitches. 
C)  Twitches sum when action potentials arrive well separated in time. 
D)  The number of motor units activated and the frequency with which the motor units fire determine the level of tension in a muscle. 
E)  Summing of twitches occurs because ATP pumps in the sarcoplasmic reticulum are unable to clear ATP from the sarcoplasm between action potentials.

Question 15

Refer to the figure.   If the purple structure labeled 2 was not present, what would be the most likely position for the structure labeled 5?

Accepted Answer

A)  Bound to one of the green structures labeled 3 
B)  Bound somewhere along the blue structure labeled 1 
C)  Bound to the tan structure labeled 4 
D)  Released from the tan structure labeled 4 and bound somewhere along the blue structure labeled 1 
E)  Released from the structure labeled 4 and bound to one of the structures labeled 3 
A)  Bound to one of the green structures labeled 3 
B)  Bound somewhere along the blue structure labeled 1 
C)  Bound to the tan structure labeled 4 
D)  Released from the tan structure labeled 4 and bound somewhere along the blue structure labeled 1 
E)  Released from the structure labeled 4 and bound to one of the structures labeled 3

Question 16

Workers who built the U.S.Transcontinental Railroad exerted a tremendous amount of effort, creating tunnels through the Sierra Nevada Mountains by breaking down the stone bit by bit.This step-by-step deconstruction process was analogous to the work performed in the body by

Accepted Answer

A)  osteoclasts. 
B)  chondrocytes. 
C)  osteoblasts. 
D)  osteocytes. 
E)  chondroblasts. 
A)  osteoclasts. 
B)  chondrocytes. 
C)  osteoblasts. 
D)  osteocytes. 
E)  chondroblasts.

Question 17

The striated appearance of skeletal muscle is due to the

Accepted Answer

A)  dark color of actin. 
B)  multiple nuclei per fiber. 
C)  regular arrangement of filaments relative to each other. 
D)  dense array of microtubules. 
E)  dense packing of ATP molecules. 
A)  dark color of actin. 
B)  multiple nuclei per fiber. 
C)  regular arrangement of filaments relative to each other. 
D)  dense array of microtubules. 
E)  dense packing of ATP molecules.

Question 18

Muscles at joints are often arranged in antagonistic pairs of extensors and _______.

Accepted Answer

The answer of Muscles at joints are often arranged in...

Question 19

During the power stroke, myosin heads

Accepted Answer

A)  bind to actin. 
B)  release actin. 
C)  return to extended conformation. 
D)  change conformation and bend, moving the actin filament. 
E)  expose the binding site. 
A)  bind to actin. 
B)  release actin. 
C)  return to extended conformation. 
D)  change conformation and bend, moving the actin filament. 
E)  expose the binding site.

Exam 47: Musculoskeletal Systems

A sport such as weight lifting, which is very demanding and leads quickly to fatigue, is reliant on _______ fibers.

Which of the following is not one of the systems that supplies muscles with the ATP needed for contraction?

The primary determinant regarding the proportion of fast- and slow-twitch fibers in a person's skeletal muscle is

Refer to the figure. The animal shown is able to move using the circular and longitudinal musculature within each segment.In the segment labeled 1, _______, and in the segment labeled 2, _______.

When a clown at a birthday party squeezes a long balloon to twist it into a poodle or a hat, the volume of air inside the balloon stretches the balloon and extends its length and stays constant.This example is analogous to the action of muscles on the

Which statement about fast-twitch fibers is true?

Myoblasts

When animals die, the lack of ATP causes muscles to stiffen in rigor mortis because

A pair of closely related bird species includes one that migrates long distances over the course of months and another that has evolved near-flightlessness on its island home.What might you expect to find when comparing the breast muscles (used for flight) of these species?

Refer to the figure showing an earthworm. The earthworm is able to move using its _______ skeleton and body musculature.

In examining a fruit fly in flight, a researcher was able to determine that the stroke frequency of the wings is 221 strokes per second.Comparing this with flight in a zebra finch, the researcher found the stroke frequency of the wings in a zebra finch was _______ than that of the fruit fly.

_______ is the continuous activation of the contractile "machinery."

Which feature characterizes a muscle that is fully stretched?

Which statement about skeletal muscle is true?

Refer to the figure. If the purple structure labeled 2 was not present, what would be the most likely position for the structure labeled 5?

Workers who built the U.S.Transcontinental Railroad exerted a tremendous amount of effort, creating tunnels through the Sierra Nevada Mountains by breaking down the stone bit by bit.This step-by-step deconstruction process was analogous to the work performed in the body by

The striated appearance of skeletal muscle is due to the

Muscles at joints are often arranged in antagonistic pairs of extensors and _______.

During the power stroke, myosin heads

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Refer to the figure. The animal shown is able to move using the circular and longitudinal musculature within each segment.In the segment labeled 1, _, and in the segment labeled 2, _.