Deck 45: Animal Movement

Question 1

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

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

Answer 1

C

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?

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

Answer 2

C

Question 3

The contraction of skeletal muscles is based on ________.

A) actin filaments coiling up to become shorter
B) myosin filaments coiling up to become shorter
C) actin and myosin filaments both coiling up to become shorter
D) actin cross-bridges binding to myosin and undergoing a power stroke
E) myosin cross-bridges binding to actin and undergoing a power stroke

Answer 3

E

Question 4

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

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

Question 5

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

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 6

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?

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

Question 7

Compared to slow oxidative muscle fibers, those classified as fast glycolytic fibers typically have ________.

A) a higher concentration of myoglobin
B) a higher density of mitochondria
C) a darker visual appearance
D) a smaller diameter
E) less resistance to fatigue

Question 8

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

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

Question 9

All skeletal muscle fibers are ________.

A) smooth and under involuntary control
B) smooth and operate independently of other skeletal muscle fibers
C) striated and under voluntary control
D) smooth and under voluntary control
E) striated and electrically coupled to neighboring fibers

Question 10

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

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

Question 11

Skeletal muscle contraction begins when calcium ions bind to ________.

A) energized cross-bridges
B) myosin
C) actin
D) acetylcholine receptors
E) troponin

Question 12

What causes rigor mortis?

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

Question 13

When an action potential from a motor neuron arrives at the neuromuscular junction (NMJ), a series of events occurs that leads to muscle contraction. Which of the following events will occur last (that is, after all of the others)?

A) acetylcholine (ACh) release
B) action potential propagation down the T tubules
C) conformational change in troponin
D) depolarization of the muscle cell
E) release of Ca2+ from the sarcoplasmic reticulum

Question 14

Cardiac muscle cells are both ________.

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 15

The structure pictured in the figure is found in ________.

A) skeletal muscles and smooth muscles
B) cardiac muscles and skeletal muscles
C) smooth muscles and cardiac muscles
D) smooth muscles, skeletal muscles, and cardiac muscles
E) smooth muscles

Question 16

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

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

Question 17

In a relaxed skeletal muscle ________.

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 18

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

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 19

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.

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 20

Food moves along the digestive tract as the result of contractions by ________.

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

Question 21

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 ________.

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

Question 22

Muscles are joined to bones by ________.

A) ligaments
B) tendons
C) loose connective tissue
D) Haversian systems
E) spindle fibers

Question 23

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

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 24

Among these choices, the most energetically efficient locomotion per unit mass is likely ________.

A) running by a 50-gram rodent
B) running by a 40-kilogram ungulate
C) flying by a 100-gram bird
D) swimming by a 10-gram minnow (bony fish)
E) swimming by a 100-kilogram tuna (bony fish)

Question 25

The functions of the vertebrate skeleton include which of the following?
I) maintenance of body posture
II) calcium homeostasis
III) transfer of muscle forces

A) I and II
B) II and III
C) III
D) I and III
E) I, II, and III

Question 26

How does skeletal muscle return to its starting length after a contraction?

A) It lengthens itself by reversing the contraction process.
B) It undergoes recoil due to the elastic properties of tendons.
C) Antagonistic muscles work to lengthen a given muscle once it relaxes.
D) Ligaments bind muscles together

Question 27

Against which structure do the circular and longitudinal muscles of annelids work?

A) bristles
B) cuticle
C) shell
D) endoskeleton
E) hydrostatic skeleton

Question 28

Which forces are most important during terrestrial locomotion?

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 29

An endoskeleton is the primary body support for the ________.

A) annelids, including earthworms
B) insects, including beetles
C) cartilaginous fishes, including sharks
D) bivalves, including clams
E) crustaceans, including lobsters

Question 30

What cell types within bone are responsible for the breakdown of bone tissue to permit reabsorption of calcium?

A) osteoblasts
B) fibroblasts
C) osteoclasts
D) myocytes

Question 31

What is an explanation for the pectoral or breast meat of ducks being very dark in color?

A) Ducks use their wings for very short flights and need fast muscle fibers to power their take-offs.
B) Ducks are primarily swimmers and therefore do not need breast muscles full of "white meat."
C) Ducks employ intermediate muscle fibers for swimming and flying.
D) Ducks fly long distances and need myoglobin-rich slow muscle fibers to power high-endurance flights.

Question 32

Chitin is a major component of the ________.

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

Question 33

What is the best explanation for why elephants stand with a more upright posture and have relatively thicker bones than cats?

A) Cats and elephants are from different taxonomic groups and therefore differ in appearance.
B) Cats eat meat and elephants eat plants, requiring different bodies.
C) Cats are smaller and need to run faster; therefore, they have smaller bones and a crouching posture.
D) Because they have a much greater volume, elephants require a disproportionately larger cross-sectional area of their bones than cats.

Question 34

For a 100-gram animal, what is the most costly form of locomotion?

A) swimming
B) flying
C) running
D) peristalsis

Question 35

The hydrostatic skeleton of the earthworm allows it to move around in its environment by ________.

A) walking on its limbs
B) crawling with its feet
C) swimming with its setae
D) using peristaltic contractions of its circular and longitudinal muscles
E) alternating contractions and relaxations of its flagella

Question 36

The structure that connects bone to bone in vertebrate skeletal systems is a ________.

A) tendon
B) ligament
C) osteoclast
D) hydrostatic skeleton

Question 37

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

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 38

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

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 39

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

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 40

Compared to parallel muscles, pennate muscles ________.

A) produce more force and undergo greater shortening
B) produce more force and undergo less shortening
C) produce less force and undergo greater shortening
D) produce less force and undergo less shortening