Deck 34: Muscular-Skeletal Systems

Question 1

Which protein contains a binding site for ATP?

A)troponin
B)myosin
C)tropomyosin
D)myelin
E)All muscle proteins must have an ATP binding sitE.

Answer 1

B

Question 2

Vertebrate bone consists primarily of a crystalline mixture of

A)Ca²⁺,PO₄^-2.
B)Ca²⁺,SO₄^-2.
C)Ca²⁺,Cl₂.
D)Na⁺,Cl^-.
E)Adenosine,PO₄^-2.

Answer 2

A

Question 3

Muscle cells are stimulated by acetylcholine released from the terminals of

A)transverse tubules.
B)motor neuron axons.
C)sensory cell axons.
D)motor neuron dendrites.
E)sensory cell dendrites.

Answer 3

B

Question 4

What is the role of calcium in muscle contractions?

A)to break the cross-bridges as a cofactor in the hydrolysis of ATP
B)to bind with troponin,changing its shape so that binding sites on the actin filament are exposed
C)to transmit the action potential across the neuromuscular junction
D)to spread the action potential through the T-tubules
E)to re-establish the polarization of the plasma's membrane following an action potential

Question 5

During muscular contraction,cross-bridges form between _____ and _____ .

A)actin,myosin
B)actin,tropomyosin
C)myosin,troponin
D)myosin,tropomyosin
E)troponin,calmodulin

Question 6

The type of muscle that typically surrounds hollow tubes and organs like the stomach is

A)smooth muscle.
B)skeletal muscle.
C)cardiac muscle.
D)striated muscle.
E)voluntary musclE.

Question 7

In muscle function at the sarcomere level,the formation of cross-bridges is regulated by the binding of ___ ions to ____.

A)calcium,troponin
B)calcium,tropomyosin
C)calcium,myosin
D)sodium,troponin
E)sodium,tropomyosin

Question 8

What are some of the disadvantages to having an exoskeleton?

A)Vulnerability during molting
B)Bulkiness reduces ability to move
C)Vulnerability to dessication
D)Bulkiness makes animal heavy

Question 9

A new muscle is found in an undiscovered species and your HYPERLINK "#" job is to classify the muscle type.When examined under a microscope there does not appear to be any straitions.When stimulated,muscle contraction time is very slow,around 30 seconds.When observed in a fully anesthetized specimen,the muscle is continuously contrating.What muscle type does this myster muscle most likely belong to?

A)Cardiac muscle
B)Skeletal muscle
C)Smooth muscle

Question 10

A bone soaked in acid for an extended period will become rubbery;you can bend it in half,twist it,sometimes even tie it into a knot! What aspect(s)of the bone's composition do you think has changed due to the acid?

A)The acid removed the inorganic,mineral components of the bone.
B)The acid removed the HYPERLINK "#" collagen from the bone.
C)The acid added Ca²⁺ to the bone.
D)Nothing.Over time,bones naturally become rubbery due to decomposition.
E)The osteoblasts are stimulated by the acid to secrete more HYPERLINK "#" collagen

Question 11

For the hierarchy of skeletal muscle organization,which accurately lists the order of structures from "small" to "big"?

A)sarcomere,myofibril,muscle fiber,motor unit
B)myofibril,muscle fiber,sarcomere,motor unit
C)motor unit,myofibril,muscle fiber,sarcomere
D)motor unit,sarcomere,muscle fiber,myofibril
E)None of the choices are correct.

Question 12

Arthropod exoskeletons are composed primarily of

A)chitin.
B)calcium carbonate.
C)collagen.
D)cartilage.
E)sclerotin.

Question 13

Determine what type of skeletal anatomy is being described in the following account.This skeletal system is found in both terrestrial and aquatic animals.It provides an anchor for muscle attachment and thus aids in locomotion.It is composed of minerals and helps support and protect the rest of the body.

A)An endoskeleton
B)An exoskeleton
C)Neither an endoskeleton nor an exoskeleton
D)Both an endoskeleton and an exoskeleton

Question 14

A fish will rapidly dart away from a sudden disturbance,like a pebble thrown into the water.Ususally the fish only swims a short distance before resuming normal,slower locomotion.What type of skeletal muscle fibers does the fish use when darting away?

A)Slow-oxidative
B)Fast-oxidative
C)Fast-glycolytic

Question 15

What is the correct sequence of events in cross-bridge cycling?

A)Myosin cross-bridge binds to actin,the powerstroke moves the thin filament relative to the thick filament,ATP binds to myosin and cross-bridge detachment occurs,ATP is hydrolyzed and the myosin head is "cocked"
B)The powerstroke moves the thin filament relative to the thick filament,myosin cross-bridge binds to actin,ATP binds to myosin and cross-bridge detachment occurs,ATP is hydrolyzed and the myosin head is "cocked"
C)Myosin cross-bridge binds to actin,ATP is hydrolyzed and the myosin head is "cocked," the powerstroke moves the thin filament relative to the thick filament,ATP binds to myosin and cross-bridge detachment occurs
D)Myosin cross-bridge binds to actin,ATP binds to myosin and cross-bridge detachment occurs,the powerstroke moves the thin filament relative to the thick filament,ATP is hydrolyzed and the myosin head is "cocked"
E)These events can occur in any sequence without affecting muscle function.

Question 16

Release of cross-bridges depends most directly on

A)calcium ions.
B)potassium ions.
C)adenosine diphosphate.
D)adenosine triphosphate.
E)creatine phosphatE.

Question 17

What structural component in skeletal and cardiac muscle conducts action potentials from the outer surface of the muscle fiber inside to the myofibrils?

A)actin
B)tropomyosin
C)troponin
D)transverse tubule
E)None of thesE.

Question 18

Each skeletal muscle cell constitutes a single

A)motor unit.
B)muscle fiber.
C)sarcolemma.
D)myofibril.
E)sarcomerE.

Question 19

The primary reservoir for calcium that is released during excitation-contraction coupling in a skeletal muscle fiber is the

A)sarcoplasmic reticulum.
B)endoplasmic reticulum.
C)transverse tubules.
D)Golgi bodies.
E)troponin.

Question 20

The thick filament is composed almost entirely of _____ molecules.

A)actin
B)myosin
C)troponin
D)tropomyosin
E)thrombin

Question 21

When experimentally applying alpha-bungarotoxin to a muscle,you find that it does not contract when the motor neuron leading to it is electrically stimulated.Knowing that this toxin blocks acetylcholine receptors,what can you conclude about the failure to contract?

A)A contraction fails to occur because this toxin prevents cross-bridge formation and thereby directly prevents contraction.
B)A contraction fails to occur because acetylcholine is not released from the motor neuron.
C)A contraction fails to occur because this toxin directly prevents calcium ion release from intracellular stores.
D)A contraction fails to occur because an action potential is not generated in the muscle cell.
E)A contraction fails to occur because neurotransmitter release by the motor neuron is blocked at the neuromuscular junction.

Question 22

You would expect to find more mitochondria in glycolytic muscle fibers than in oxidative muscle fibers.

Question 23

The breast muscle of turkeys and chickens is usually referred to as light meat,whereas that of wild ducks and geese is described as dark meat.Muscle with more mitochondria and myoglobin are darker compared to muscle with less mitochondria and myoglobin.What can you conclude about these groups of birds?

A)Turkeys and chickens are not closely related to ducks and geese.
B)Turkeys and chickens do not fly for sustained periods,whereas wild ducks and geese do.
C)The muscles of ducks and geese do not contain myosins,whereas the muscles of turkeys and chickens do.
D)The darker body color of ducks and geese provides protective camouflage against predators.

Question 24

A new species of mouse is discovered that can sprint extraordinarily rapidly but also fatigues quickly.How would you expect its muscle composition to compare to that of an ordinary house mouse?

A)more slow oxidative fibers
B)more slow glycolytic fibers
C)more fast oxidative fibers
D)more fast glycolytic fibers
E)fewer fast glycolytic fibers

Question 25

When an organism dies,its muscles remain in a contracted state termed rigor mortis for a brief period of time.Contributing most directly to this phenomenon is

A)the inability to synthesize actin and myosin.
B)the absence of an oxygen supply to muscle.
C)the lack of ATP to break cross-bridges between thick and thin filaments.
D)the lack of calcium to bind to troponin.

Question 26

The acetylcholine receptor is a ligand-gated channel that produces

A)Repolarization by activating second messenger systems within the muscle fiber.
B)Depolarization by allowing K⁺ ions to leave the muscle fiber.
C)Depolarization by allowing Cl^- ions to enter the muscle fiber.
D)Depolarization by allowing Na⁺ ions to enter the muscle fiber.
E)Hyperpolarization by allowing Na⁺ ions to exit the muscle fiber.

Question 27

You would expect to find higher myoglobin levels in oxidative muscle fibers than in glycolytic muscle fibers.

Question 28

In the disease myasthenia gravis,there is a deficiency of acetylcholine receptors at the neuromuscular junction.This shortage blocks contraction by preventing

A)generation of action potentials in the motor neuron.
B)opening of the T-tubule system.
C)release of Ca²⁺ from the sarcoplasmic reticulum.
D)the interaction of troponin with tropomyosin.
E)generation of action potentials in the muscle fiber.

Question 29

Imagine you have extracted myosin molecules from both fast and slow twitch muscle fibers and are measuring the rate at which these proteins hydrolyze ATP.What would these relative rates of ATP hydrolysis be?

A)fast twitch fiber > slow twitch fiber
B)slow twitch fiber > fast twitch fiber
C)slow twitch fiber = fast twitch fiber

Question 30

The fact that a quarterback can throw a football at approximately 50 miles per hour means that the muscles powering this throw must also be shortening at 50 miles per hour.