Question 1

​Fast and ____ muscle fibers contract rapidly but do not produce sustained contractions, whereas slow and ____ muscle fibers contract slowly but can produce energy for long periods of time via aerobic respiration.
A)​white; red
B)​red; white
C)​striated; unstriated
D)voluntary; involuntary
E)​unstriated; striated​

Accepted Answer

Fast and white muscle fibers contract rapidly but fatigue quickly, making them suitable for short bursts of power. Slow and red muscle fibers contract more slowly but can sustain contractions for longer, thanks to their high myoglobin content and greater blood supply, which supports aerobic respiration.

Question 2

Which organisms have exoskeletons?
A)earthworms
B)humans
C)sea anemones
D)insects and clams
E)amphibians

Accepted Answer

Only insects and clams have exoskeletons. Earthworms, humans, sea anemones, and amphibians do not have exoskeletons.

Question 3

A sphincter is a ____.
A)ring of smooth muscle in a tubular organ or body opening
B)strap of connective tissue that connects bone to bone
C)strap of connective tissue that connects muscle to bone
D)ring of muscle at a body opening
E)longitudinal muscle at a body opening

Accepted Answer

A sphincter is a ring of muscle that serves as a valve to control the opening and closing of a body opening, such as the anal sphincter or the lower esophageal sphincter.

Question 4

The bone in the upper arm is the ____.
A)radius
B)ulna
C)tibia
D)humerus
E)femur

Accepted Answer

The bone in the upper arm is called the humerus.

Question 5

Which animals have a cartilaginous skeleton as an adult?
A)sharks
B)reptiles
C)humans
D)houseflies
E)earthworms

Accepted Answer

Sharks have a cartilaginous skeleton as an adult, which is made of flexible cartilage rather than bone.

Question 6

The embryonic skeleton of all vertebrates is made of ____.
A)yellow bone marrow
B)elastic tissue
C)loose connective tissue
D)cartilage
E)muscle tissue

Accepted Answer

The embryonic skeleton of all vertebrates is made of cartilage. As the embryo develops, it is gradually replaced by bone tissue through a process called ossification, which begins in the center of most bones at about six weeks after fertilization. This process continues throughout childhood and adolescence.

Question 7

The most common type of joint is the ____ joint.
A)bony
B)cartilaginous
C)elastic
D)fibrous
E)synovial

Accepted Answer

Synovial joints are the most common type of joint in the body, accounting for about 80% of all joints. They are characterized by a fluid-filled space between the bones, allowing for smooth movement and cushioning. Bony joints (A) occur where bones fuse together, cartilaginous joints (B) are connected by cartilage, elastic joints (C) are found in structures like the ear and allow for flexibility, and fibrous joints (D) are held together by dense fibrous connective tissue and allow for limited movement.

Question 8

Which skeletal muscle component includes all the others?
A)actin
B)myofibril
C)myosin
D)sarcomere
E)muscle fiber

Accepted Answer

A muscle fiber is a single cell that contains many nuclei and is composed of many myofibrils, which in turn are made up of repeating units called sarcomeres. Sarcomeres contain the actin and myosin filaments necessary for muscle contraction. Therefore, the muscle fiber includes all the other components listed.

Question 9

The bright red color of red muscle fibers comes from the presence of ____, exemplifying their role in producing ATP mainly by aerobic respiration.
A)blood
B)hemoglobin
C)carbon dioxide
D)sarcomeres
E)myoglobin

Accepted Answer

The bright red color of red muscle fibers comes from the presence of myoglobin, which stores oxygen and allows for aerobic respiration to occur in the muscle cell.

Question 10

Calcium release from bones is triggered by _____.
A)estrogen
B)progesterone
C)testosterone
D)parathyroid hormone
E)growth hormone

Accepted Answer

Calcium release from bones is triggered by parathyroid hormone.

Question 11

The arrival of an action potential causes the release of ____ by the ____.
A)calcium; myofibrils
B)calcium; sarcoplasmic reticulum
C)sodium; myofibrils
D)sodium; sarcoplasmic reticulum
E)actin; myosin heads

Accepted Answer

When an action potential arrives in the muscle cell, it travels down the T-tubules which are invaginations of the sarcolemma (cell membrane) that allow the action potential to reach the sarcoplasmic reticulum (SR). The SR then releases stored calcium ions into the cytoplasm of the muscle cell. This calcium release triggers the contraction of the muscle fibers. Therefore, the correct answer is B - calcium is released by the sarcoplasmic reticulum in response to an action potential.

Question 12

The main energy for prolonged muscle work comes from ____.
A)stored ATP
B)stored creatine phosphate
C)fermentation of carbohydrates
D)aerobic respiration of carbohydrates and fats
E)stored ADP

Accepted Answer

Prolonged muscle work requires energy that is sustained for longer periods of time, which is primarily provided by aerobic respiration of carbohydrates and fats. Stored ATP and creatine phosphate can provide immediate energy for short bursts of muscle activity, and fermentation of carbohydrates can provide energy during anaerobic exercise, but these sources are not sufficient for prolonged muscle work. Stored ADP is not a source of energy.

Question 13

To move, an animal must expend ____ to overcome the effects of ____ and friction.
A)oxygen; respiration
B)muscle contractions; fatigue
C)nutrients; motion
D)glucose; movement
E)energy; gravity

Accepted Answer

To move, an animal must expend energy to overcome both gravity (which affects movement in any direction) and friction (which affects movement across a surface). Therefore, the best answer is E) energy; gravity. Choices A, B, C, and D are incorrect as they do not address the specific factors of gravity and friction that must be overcome for movement.

Question 14

Four of the five answers listed below are health impacts associated with prolonged sitting. Select the exception.
A)decreased LDL production
B)increased blood lipid concentration
C)increased cardiovascular disease
D)increased diabetes
E)increased uptake of fatty acids from the blood

Accepted Answer

Prolonged sitting is associated with decreased uptake of fatty acids from the blood, not increased. The other options (A, B, C, D) are known health impacts of prolonged sitting, such as increased risk of cardiovascular disease, diabetes, and changes in blood lipid concentrations.

Question 15

Most skeletal muscles cause movement of a body part by\ ____.
A)stimulating the contraction of another muscle
B)pushing on a bone
C)pulling on a bone
D)stimulating a joint to contract
E)pushing on a ligament

Accepted Answer

Skeletal muscles are attached to bones by tendons and when they contract, they pull on the bones, causing movement at joints. Therefore, the correct choice is C) pulling on a bone.

Question 16

The ability to extend a leg originates from ____.
A)contraction of ligaments
B)contraction of tendons
C)contraction of a muscle
D)lengthening of a muscle
E)relaxation of a synovial joint

Accepted Answer

The ability to extend a leg is due to the contraction of a muscle, specifically the quadriceps muscle group. Other structures such as ligaments, tendons, and synovial joints may be involved in the overall movement, but the primary force behind leg extension is muscle contraction.

Question 17

Most of the ATP used by a muscle during intense activity is produced by ____.
A)creatine phosphate
B)lactate fermentation
C)aerobic respiration
D)glucose
E)pyruvate

Accepted Answer

During intense activity, muscles primarily rely on lactate fermentation for ATP production due to the rapid energy demand that exceeds the oxygen supply for aerobic respiration.

Question 18

The kneecap is the ____.
A)hyoid
B)patella
C)scapula
D)clavicle
E)phalanx

Accepted Answer

The kneecap is also known as the patella.

Question 19

The basic unit of contraction in a skeletal muscle is the ____.
A)myofibril
B)sarcomere
C)muscle fiber
D)myosin filament
E)actin filament

Accepted Answer

The sarcomere is the smallest contractile unit of a skeletal muscle fiber. It is made up of overlapping thick (myosin) and thin (actin) filaments. When the muscle contracts, these filaments slide past each other, causing the sarcomere to shorten and the muscle to contract.

Question 20

Four of the five answers listed below are molecules that directly participate in muscle contraction within a muscle fiber. Select the exception.
A)acetylcholine
B)ATP
C)calcium
D)actin
E)myosin

Accepted Answer

Acetylcholine is a neurotransmitter that binds to receptors on the muscle fiber to initiate the release of calcium ions, which in turn triggers muscle contraction. However, acetylcholine itself does not directly participate in muscle contraction within the muscle fiber. The other options (ATP, calcium, actin, and myosin) all play direct roles in muscle contraction.

Quiz 32: Structural Support and Movement

Fast and muscle fibers contract rapidly but do not produce sustained contractions, whereas slow and muscle fibers contract slowly but can produce energy for long periods of time via aerobic respiration.

Which organisms have exoskeletons?

A sphincter is a ____.

The bone in the upper arm is the ____.

Which animals have a cartilaginous skeleton as an adult?

The embryonic skeleton of all vertebrates is made of ____.

The most common type of joint is the ____ joint.

Which skeletal muscle component includes all the others?

The bright red color of red muscle fibers comes from the presence of ____, exemplifying their role in producing ATP mainly by aerobic respiration.

Calcium release from bones is triggered by _____.

The arrival of an action potential causes the release of by the .

The main energy for prolonged muscle work comes from ____.

To move, an animal must expend to overcome the effects of and friction.

Four of the five answers listed below are health impacts associated with prolonged sitting. Select the exception.

Most skeletal muscles cause movement of a body part by\ ____.

The ability to extend a leg originates from ____.

Most of the ATP used by a muscle during intense activity is produced by ____.

The kneecap is the ____.

The basic unit of contraction in a skeletal muscle is the ____.

Four of the five answers listed below are molecules that directly participate in muscle contraction within a muscle fiber. Select the exception.