Question 1

Which statement best describes how an earthworm moves?

Accepted Answer

A)  It stretches its longitudinal muscles and pushes its fluid-filled body cavity forward. 
B)  It forms pseudopods that ooze forward or backward. 
C)  It uses the coordinated beating of many cilia. 
D)  It alternates contractions of longitudinal and circular muscles. 
E)  It contracts longitudinal muscles, which puts pressure on the hydrostatic skeleton and causes it to extend.

Question 2

Refer to the figure showing various stages of a contraction cycle in a sarcomere.  What has happened between panels A and B that has allowed myosin to attach to actin?

Accepted Answer

The answer of Refer to the figure showing various stages...

Question 3

Performing a chin-up is usually particularly difficult at the very end of the exercise because

Accepted Answer

A)  when the muscle is fully contracted, it is exerting a maximum amount of force. 
B)  there is so much overlap between actin and myosin in the sarcomeres. 
C)  of psychological fatigue that is a metabolic by-product of the exertion. 
D)  of the necessary switch from fast- to slow-twitch fibers. 
E)  the sarcomeres cannot shorten beyond their resting length.

Question 4

Which of the following characterizes cardiac muscle?

Accepted Answer

A)  Its cells have numerous nuclei similar to skeletal muscle. 
B)  Its striated appearance results from the regular arrangement of actin and myosin. 
C)  Its cells are larger than those of any skeletal muscle. 
D)  Its cells are long and unbranched. 
E)  Its individual cells are not connected by specialized junctions.

Question 5

Refer to figure showing the knee joint and the bones and muscles of the human leg.  Structure 1 is a _______ and attaching ______.Structure 2 is a _______ and attaching _______.

Accepted Answer

A)  tendon; muscle to bone; ligament; bone to bone 
B)  ligament; muscle to bone; tendon; bone to bone 
C)  ligament; muscle to joint; tendon; bone to bone 
D)  tendon; bone to bone; ligament; muscle to bone 
E)  ligament; bone to bone; tendon; joint to joint

Question 6

Which statement about exoskeletons is true?

Accepted Answer

A)  During molting, the old exoskeleton is reabsorbed and a new exoskeleton forms. 
B)  A clam shell is not an exoskeleton. 
C)  The arthropod cuticle is secreted by a layer of cells external to the exoskeleton. 
D)  The inner layer of the arthropod exoskeleton provides a surface for muscle attachment. 
E)  The arthropod exoskeleton is thickened at the joints.

Question 7

You come across several invertebrate organisms crawling through the sand.You notice that they have a soft body wall, and when you dissect one, you see that it has no rigid structures inside the body.This organism most likely

Accepted Answer

A)  has no skeletal system. 
B)  uses a skeletal system built by osteoblasts. 
C)  attaches its internal muscles to an exoskeleton. 
D)  uses a hydrostatic skeleton to move. 
E)  uses a skeletal system composed of cartilage.

Question 8

Prior to running a marathon, you decide to try carbo-loading in order to increase the amount of _______ stored in your muscles.

Accepted Answer

The answer of Prior to running a marathon, you decide...

Question 9

Insect flight muscles can contract as fast as _______ times per second, which is _______ hummingbird flight muscles.

Accepted Answer

A)  50; slower than 
B)  100; slower than 
C)  500; the same as 
D)  1,000; the same as 
E)  1,000; many times faster than

Question 10

Which of the following is a major difference between strength training and aerobic exercise?

Accepted Answer

A)  Only strength training increases endurance by creating more muscle fibers. 
B)  Only aerobic exercise increases the size of muscle fibers. 
C)  Only strength training increases the production of myoglobin. 
D)  Only aerobic exercise increases the oxidative capacity of muscles. 
E)  Only strength training increases the density of capillaries delivering oxygen to the muscles.

Question 11

Transverse (T) tubules of skeletal muscle cells

Accepted Answer

A)  are continuous with the plasma membrane of a muscle cell. 
B)  project from the cell surface. 
C)  transmit action potentials from the endoplasmic reticulum (ER). 
D)  are continuous with the sarcoplasmic reticulum. 
E)  are reservoirs for calcium ions.

Question 12

Which statement characterizes skeletal muscle?

Accepted Answer

A)  It is responsible for involuntary movements. 
B)  Its cells are uninucleate. 
C)  Its cells are branched. 
D)  It helps maintain posture. 
E)  It is responsible for the beating of the heart.

Question 13

Which feature characterizes the glycolytic system for supplying ATP to muscle cells?

Accepted Answer

A)  It takes place in the mitochondria and involves the electron transport chain. 
B)  The ATP it generates is available to myosin filaments once the level of oxidative metabolism has peaked. 
C)  It requires oxygen. 
D)  It activates after 10 minutes. 
E)  It generates lactic acid.

Question 14

Cartilage

Accepted Answer

A)  contains a matrix that lacks collagen fibers. 
B)  is found in parts of the mammalian endoskeleton where rigidity and hardness are required. 
C)  is not stiff enough to be supportive. 
D)  is a principal component of the embryonic skeleton in humans. 
E)  is not present in any structures of the adult human.

Question 15

Hydrostatic skeletons are found in annelids, such as earthworms, and in cnidarians, such as hydras.Would a hydrostatic skeleton support locomotion in a large terrestrial animal? Why or why not?

Accepted Answer

The answer of Hydrostatic skeletons are found in annelids, such...

Question 16

The glycolytic system by which muscles obtain ATP

Accepted Answer

A)  relies on creatine phosphate. 
B)  is also referred to as the immediate system. 
C)  is the most efficient means of producing ATP. 
D)  produces lactic acid as a by-product. 
E)  completely metabolizes carbohydrates and fats.

Question 17

Fast-twitch fibers are also called _______ muscle because they contain few mitochondria and little or no myoglobin.

Accepted Answer

The answer of Fast-twitch fibers are also called _______ muscle...

Question 18

Refer to the graph showing the capacity of three systems that provide ATP for muscle contraction.  A short-distance world-record champion running a 400-meter race in 43 seconds relies mostly on

Accepted Answer

A)  the system of curve A. 
B)  the system of curve B. 
C)  the system of curve C. 
D)  the anaerobic production of ATP to meet the needs of muscles. 
E)  both the systems of curve A and B.

Question 19

Refer to the figure relating sarcomere length to the force a muscle can generate.  At the beginning of a pull-up, the sarcomeres in your biceps are best represented by _______.As you get within an inch of the bar, the same sarcomeres are best represented by _______.

Accepted Answer

A)  A and 1; B and 2 
B)  B and 1; A and 3 
C)  A and 2; B and 3 
D)  B and 3; A and 2 
E)  A and 3; B and 1

Question 20

Which pairing between body region and type of joint is correct?

Accepted Answer

A)  Shoulder: ball-and-socket 
B)  Knee: pivot 
C)  Wrist: ellipsoid 
D)  Elbow: hinge 
E)  Ankle: saddle

Exam 47: Musculoskeletal Systems