Question 1

Summation of frequent muscle twitches to give maximum contraction is called

Accepted Answer

A)  motor unit summation. 
B)  twitch. 
C)  facilitation. 
D)  tetanus. 
E)  muscle tone. 
A)  motor unit summation. 
B)  twitch. 
C)  facilitation. 
D)  tetanus. 
E)  muscle tone.

Question 2

Which of the following limits a muscle's capacity to be shortened?

Accepted Answer

A)  Bones, which eventually impede further contraction. 
B)  The overlap of actin and myosin, which eventually causes myosin to push against the Z line. 
C)  The overlap of actin and myosin, which eventually causes actin to push against the Z line. 
D)  The water component of fiber cell cytoplasm, which is incompressible. 
E)  All of the above 
A)  Bones, which eventually impede further contraction. 
B)  The overlap of actin and myosin, which eventually causes myosin to push against the Z line. 
C)  The overlap of actin and myosin, which eventually causes actin to push against the Z line. 
D)  The water component of fiber cell cytoplasm, which is incompressible. 
E)  All of the above

Question 3

The role of cartilage in the skeleton is to

Accepted Answer

A)  bear heavy loads. 
B)  add flexibility. 
C)  be lightweight. 
D)  sustain vibrations. 
E)  grow rapidly. 
A)  bear heavy loads. 
B)  add flexibility. 
C)  be lightweight. 
D)  sustain vibrations. 
E)  grow rapidly.

Question 4

Long bones begin as _______ bones. At maturity, the shaft of a long bone consists of a _______ of _______ bone.

Accepted Answer

A)  dermal; cylinder; compact 
B)  dermal; solid rod; cancellous 
C)  cartilage; cylinder; compact 
D)  cartilage; cylinder; cancellous 
E)  cartilage; solid rod; compact 
A)  dermal; cylinder; compact 
B)  dermal; solid rod; cancellous 
C)  cartilage; cylinder; compact 
D)  cartilage; cylinder; cancellous 
E)  cartilage; solid rod; compact

Question 5

Slow-twitch fibers are also called _______.

Accepted Answer

oxidative

Question 6

Unlike humans, kangaroos can increase their movement speed without an increase in their metabolic rate because

Accepted Answer

A)  their diet is more energy-rich than ours is. 
B)  they have more mitochondria per cell than we do. 
C)  the recoil in their elastic tendons helps power each jump. 
D)  they convert starch directly to ATP without first hydrolyzing it to glucose. 
E)  they alternate which foot they use each time they jump. 
A)  their diet is more energy-rich than ours is. 
B)  they have more mitochondria per cell than we do. 
C)  the recoil in their elastic tendons helps power each jump. 
D)  they convert starch directly to ATP without first hydrolyzing it to glucose. 
E)  they alternate which foot they use each time they jump.

Question 7

Cells that break down or resorb bone are the _______.

Accepted Answer

The answer of Cells that break down or resorb bone...

Question 8

If we compare the jaw and knee joints as lever systems,

Accepted Answer

A)  the jaw joint can apply greater compressional forces. 
B)  their ratios of power arm to load arm are about the same. 
C)  the knee joint has greater rotational abilities. 
D)  the knee joint has a greater ratio of power arm to load arm. 
E)  only the jaw is a hinged joint. 
A)  the jaw joint can apply greater compressional forces. 
B)  their ratios of power arm to load arm are about the same. 
C)  the knee joint has greater rotational abilities. 
D)  the knee joint has a greater ratio of power arm to load arm. 
E)  only the jaw is a hinged joint.

Question 9

Myofibrils are organized into

Accepted Answer

A)  sarcolemmas. 
B)  neurilemmas. 
C)  sarcoplasmic reticulae. 
D)  sarcomeres. 
E)  myomeres. 
A)  sarcolemmas. 
B)  neurilemmas. 
C)  sarcoplasmic reticulae. 
D)  sarcomeres. 
E)  myomeres.

Question 10

A benefit of an arthropod's exoskeleton is that it

Accepted Answer

A)  protects against abrasion. 
B)  prevents water loss. 
C)  provides attachment sites for muscles. 
D)  bends at the animal's joints. 
E)  All of the above 
A)  protects against abrasion. 
B)  prevents water loss. 
C)  provides attachment sites for muscles. 
D)  bends at the animal's joints. 
E)  All of the above

Question 11

The last little bit of a chin-up is usually the most difficult to perform because

Accepted Answer

A)  of the lever properties of the muscle-joint interaction. 
B)  stretched sarcomeres have less overlap where cross-linking can occur. 
C)  of psychological fatigue that is a metabolic by-product of the exertion. 
D)  the necessary switch from fast- to slow-twitch fibers. 
E)  Both a and b 
A)  of the lever properties of the muscle-joint interaction. 
B)  stretched sarcomeres have less overlap where cross-linking can occur. 
C)  of psychological fatigue that is a metabolic by-product of the exertion. 
D)  the necessary switch from fast- to slow-twitch fibers. 
E)  Both a and b

Question 12

Which of the following statements about slow-twitch and fast-twitch muscles is true?

Accepted Answer

A)  One is smooth muscle and one is skeletal muscle. 
B)  They express different genes in their myosin molecules. 
C)  One occurs only in mammals. 
D)  They typically have similar numbers of mitochondria per cell. 
E)  Those with low ATPase activity compensate by quickly recycling their actin-myosin bridges. 
A)  One is smooth muscle and one is skeletal muscle. 
B)  They express different genes in their myosin molecules. 
C)  One occurs only in mammals. 
D)  They typically have similar numbers of mitochondria per cell. 
E)  Those with low ATPase activity compensate by quickly recycling their actin-myosin bridges.

Question 13

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

Accepted Answer

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

Question 14

A motor unit is best described as

Accepted Answer

A)  all the nerve fibers and muscle fibers in a single muscle bundle. 
B)  one muscle fiber and its single nerve fiber. 
C)  a single motor neuron and all the muscle fibers that it innervates. 
D)  the neuron that provides the central nervous system with information about muscle contraction. 
E)  a neuron that communicates information from sensory to motor neurons. 
A)  all the nerve fibers and muscle fibers in a single muscle bundle. 
B)  one muscle fiber and its single nerve fiber. 
C)  a single motor neuron and all the muscle fibers that it innervates. 
D)  the neuron that provides the central nervous system with information about muscle contraction. 
E)  a neuron that communicates information from sensory to motor neurons.

Question 15

Fast-twitch fibers differ from slow-twitch fibers in that

Accepted Answer

A)  they are more common in the leg muscles of champion sprinters than marathon runners. 
B)  they have more mitochondria. 
C)  they fatigue less rapidly. 
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 marathon runners. 
B)  they have more mitochondria. 
C)  they fatigue less rapidly. 
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 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. 
E)  completely metabolizes carbohydrates and fats. 
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. 
E)  completely metabolizes carbohydrates and fats.

Question 17

The rate of actin-myosin cross-bridge recycling is central to the difference between _______ and _______ fibers.

Accepted Answer

slow-twitc

Question 18

_______ are responsible for the dynamic remodeling of bone that occurs continuously.

Accepted Answer

A)  Osteoblasts 
B)  Osteoblasts and osteoclasts 
C)  Osteoclasts and osteocytes 
D)  Osteoblasts, osteoclasts, and osteocytes 
E)  Myoblasts 
A)  Osteoblasts 
B)  Osteoblasts and osteoclasts 
C)  Osteoclasts and osteocytes 
D)  Osteoblasts, osteoclasts, and osteocytes 
E)  Myoblasts

Question 19

The _______ is a highly specialized network of intracellular membranes that enables striated muscle cells to sequester and release calcium for muscle contraction.

Accepted Answer

sarcoplasm

Question 20

Fifteen minutes into a 10k run, what is the major energy source of the leg muscles?

Accepted Answer

A)  Preformed ATP 
B)  Glycolysis 
C)  Oxidative metabolism 
D)  Pyruvate and lactate 
E)  High-protein drink consumed right before the race 
A)  Preformed ATP 
B)  Glycolysis 
C)  Oxidative metabolism 
D)  Pyruvate and lactate 
E)  High-protein drink consumed right before the race

Exam 48: Musculoskeletal Systems

Summation of frequent muscle twitches to give maximum contraction is called

Which of the following limits a muscle's capacity to be shortened?

The role of cartilage in the skeleton is to

Long bones begin as _______ bones. At maturity, the shaft of a long bone consists of a _______ of _______ bone.

Slow-twitch fibers are also called _______.

Unlike humans, kangaroos can increase their movement speed without an increase in their metabolic rate because

Cells that break down or resorb bone are the _______.

If we compare the jaw and knee joints as lever systems,

Myofibrils are organized into

A benefit of an arthropod's exoskeleton is that it

The last little bit of a chin-up is usually the most difficult to perform because

Which of the following statements about slow-twitch and fast-twitch muscles is true?

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

A motor unit is best described as

Fast-twitch fibers differ from slow-twitch fibers in that

The glycolytic system by which muscles obtain ATP

The rate of actin-myosin cross-bridge recycling is central to the difference between _______ and _______ fibers.

_______ are responsible for the dynamic remodeling of bone that occurs continuously.

The _______ is a highly specialized network of intracellular membranes that enables striated muscle cells to sequester and release calcium for muscle contraction.

Fifteen minutes into a 10k run, what is the major energy source of the leg muscles?

Studying Life

Small Molecules and the Chemistry of Life

Proteins, Carbohydrates, and Lipids

Nucleic Acids and the Origin of Life

Cells: the Working Units of Life

Cell Membranes

Cell Signaling and Communication

Energy, Enzymes, and Metabolism

Pathways That Harvest Chemical Energy

Photosynthesis: Energy From Sunlight

The Cell Cycle and Cell Division

Inheritance, Genes, and Chromosomes

Dna and Its Role in Heredity

From Dna to Protein: Gene Expression

Gene Mutation and Molecular Medicine

Regulation of Gene Expression

Genomes

Recombinent Dna and Biotechnology

Differential Gene Expression in Development

Development and Evolutionary Change

Evidence and Mechanisms of Evolution

Reconstructing and Using Phylogenies

Species and Their Formation

Evolution of Genes and Genomes

The History of Life on Earth

Bacteria and Archaea: the Prokaryotic Domains

The Origin and Diversification of Eukaryotes

Plants Without Seeds: From Water to Land

The Evolution of Seed Plants

Fungi: Recyclers, Pathogens, Parasites, and Plant Partners

Animal Origins and the Evolution of Body Plans

Protostome Animals

Deuterostome Animals

The Plant Body

Transport in Plants

Plant Nutrition

Regulation of Plant Growth

Reproduction in Flowering Plants

Plant Responses to Environmental Challenges

Physiology, Homeostasis, and Temperature Regulation

Animal Hormones

Immunology: Animal Defense Systems

Animal Reproduction

Animal Development

Neurons and Nervous Systems

Sensory Systems

The Mammalian Nervous System: Structure and Higher Function

Gas Exchange in Animals

Circulatory Systems

Nutrition, Digestion, and Absorption

Salt and Water Balance and Nitrogen

Animal Behavior

Ecology and the Distribution of Life

Population Ecology

Species Interaction and Coevolution

Community Ecology

Ecosystems and Global Ecology

Conservation Biology

Filters

Long bones begin as ___ bones. At maturity, the shaft of a long bone consists of a _ of _____ bone.

The rate of actin-myosin cross-bridge recycling is central to the difference between _ and _ fibers.