Question 1

A muscle fiber generates maximum contractile force when

Accepted Answer

A)  it has been exposed to creatine phosphate. 
B)  it receives repeated action potentials from a motor neuron. 
C)  some of the myofibrils contract and then relax at the same time. 
D)  it has been stretched excessively. 
A)  it has been exposed to creatine phosphate. 
B)  it receives repeated action potentials from a motor neuron. 
C)  some of the myofibrils contract and then relax at the same time. 
D)  it has been stretched excessively.

Question 2

What is the function of the sarcoplasmic reticulum?

Accepted Answer

A)  Provides support 
B)  Storage of calcium ions 
C)  Contraction 
D)  Storage of ATP 
A)  Provides support 
B)  Storage of calcium ions 
C)  Contraction 
D)  Storage of ATP

Question 3

Which of the following is TRUE with regard to the sliding filament mechanism of muscle contraction?

Accepted Answer

A)  When a muscle fiber is contracting, the thin fibers are connected to the thick fibers. 
B)  When actin pushes the Z discs farther apart, the muscle contracts. 
C)  The muscle relaxes when calcium ions are released into the fluid surrounding the thick and thin filaments. 
D)  The energy for contraction comes from the breakdown of actin into myosin. 
A)  When a muscle fiber is contracting, the thin fibers are connected to the thick fibers. 
B)  When actin pushes the Z discs farther apart, the muscle contracts. 
C)  The muscle relaxes when calcium ions are released into the fluid surrounding the thick and thin filaments. 
D)  The energy for contraction comes from the breakdown of actin into myosin.

Question 4

Describe some of the important functions of the vertebrate endoskeleton.

Accepted Answer

The vertebrate endoskeleton allows locom

Question 5

If a doctor tells a patient that he has broken an axial bone, to which of these bones would the doctor be referring?
A) Radius
B) Ilium
C) Clavicle
D) Vertebra
E) Fibula

Accepted Answer

The answer of If a doctor tells a patient that...

Question 6

Arrange these muscle tissue groupings in order, from most inclusive to least inclusive: sarcomere, motor unit, thick and thin filaments, myofibril, muscle fiber.

Accepted Answer

motor unit, muscle f

Question 7

Which molecule contains a binding site for the attachment of myosin heads?

Accepted Answer

A)  Troponin 
B)  Tropomyosin 
C)  Actin 
D)  Myoglobin 
A)  Troponin 
B)  Tropomyosin 
C)  Actin 
D)  Myoglobin

Question 8

Bones store calcium and

Accepted Answer

A)  glycogen. 
B)  amino acids. 
C)  phosphorus. 
D)  manganese. 
E)  magnesium. 
A)  glycogen. 
B)  amino acids. 
C)  phosphorus. 
D)  manganese. 
E)  magnesium.

Question 9

The type of ion found in high concentrations in the sarcoplasmic reticulum is .

Accepted Answer

The answer of The type of ion found in high...

Question 10

When a muscle fiber receives an action potential from a neuron, how many sarcomeres in the fiber contract?

Accepted Answer

A)  All of the sarcomeres in the fiber contract. 
B)  The number that contracts is inversely proportional to the strength of the action potential. 
C)  The number that contracts is directly proportional to the strength of the action potential. 
D)  Approximately one half of the sarcomeres in the fiber contract. 
A)  All of the sarcomeres in the fiber contract. 
B)  The number that contracts is inversely proportional to the strength of the action potential. 
C)  The number that contracts is directly proportional to the strength of the action potential. 
D)  Approximately one half of the sarcomeres in the fiber contract.

Question 11

Osteoporosis is the

Accepted Answer

A)  conversion of cartilage to bone in the developing embryo. 
B)  painful swelling of joints. 
C)  loss of calcium from hard bone. 
D)  detachment of a ligament from a bone. 
A)  conversion of cartilage to bone in the developing embryo. 
B)  painful swelling of joints. 
C)  loss of calcium from hard bone. 
D)  detachment of a ligament from a bone.

Question 12

What is the function of troponin and tropomyosin during skeletal muscle contraction?

Accepted Answer

A)  To increase the amount of calcium entering the muscle fiber 
B)  To regulate bonding between actin and myosin 
C)  To remove calcium from the muscle fiber 
D)  To prevent over- contraction of muscle fibers 
E)  To generate an action potential 
A)  To increase the amount of calcium entering the muscle fiber 
B)  To regulate bonding between actin and myosin 
C)  To remove calcium from the muscle fiber 
D)  To prevent over- contraction of muscle fibers 
E)  To generate an action potential

Question 13

The anterior cruciate ligament (ACL) is one of the major knee joint ligaments in humans, and damage to this ligament is fairly common in athletes. An ACL tear is most often a sports- related injury but can also result from accidents, falls, and work- related injuries. Most sports- related ACL tears occur when a person pivots or lands fr a jump. Based on this information as well as your knowledge of ligaments, which of the following occurs in an athlete w torn ACL?

Accepted Answer

A)  Instability or weakness of the knee joint 
B)  Rapid firing of all the neurons involved in the affected motor unit 
C)  Inability to contract the quadriceps 
D)  Inability to relax the quadriceps 
A)  Instability or weakness of the knee joint 
B)  Rapid firing of all the neurons involved in the affected motor unit 
C)  Inability to contract the quadriceps 
D)  Inability to relax the quadriceps

Question 14

Both smooth and cardiac muscle fibers

Accepted Answer

A)  possess intercalated discs. 
B)  contain a single nucleus. 
C)  have multiple nuclei. 
D)  are striated. 
A)  possess intercalated discs. 
B)  contain a single nucleus. 
C)  have multiple nuclei. 
D)  are striated.

Question 15

Cartilage primarily consists of

Accepted Answer

A)  magnesium and manganese. 
B)  actin. 
C)  glycoproteins and collagen. 
D)  myosin. 
E)  calcium and phosphate. 
A)  magnesium and manganese. 
B)  actin. 
C)  glycoproteins and collagen. 
D)  myosin. 
E)  calcium and phosphate.

Question 16

Some joints, such as those joining the bones of the skull, are immobile and do not allow the two bones involved to move.

Accepted Answer

A) True 
 B)False

Question 17

What might be a major disadvantage of having a ball- and- socket joint, rather than a hinge joint, in the human knee?

Accepted Answer

A)  Decreased muscle strength 
B)  Reduced ability to move the lower leg 
C)  Decreased joint flexibility 
D)  Decreased joint stability 
A)  Decreased muscle strength 
B)  Reduced ability to move the lower leg 
C)  Decreased joint flexibility 
D)  Decreased joint stability

Question 18

Skeletal muscle appears striped because of the

Accepted Answer

A)  way the sarcoplasmic reticulum wraps around the myofibril. 
B)  arrangement of ions across the sarcoplasmic reticulum membrane. 
C)  orientation of T tubules. 
D)  arrangement of thick and thin filaments. 
E)  accessory proteins in thin filaments. 
A)  way the sarcoplasmic reticulum wraps around the myofibril. 
B)  arrangement of ions across the sarcoplasmic reticulum membrane. 
C)  orientation of T tubules. 
D)  arrangement of thick and thin filaments. 
E)  accessory proteins in thin filaments.

Question 19

Bone- forming cells are known as

Accepted Answer

A)  osteoclasts. 
B)  osteoblasts. 
C)  osteocytes. 
D)  chondrocytes. 
A)  osteoclasts. 
B)  osteoblasts. 
C)  osteocytes. 
D)  chondrocytes.

Question 20

This figure illustrates what type of joint?

Accepted Answer

A)  Plane 
B)  Hinge 
C)  Ball- and- socket 
D)  Suture 
A)  Plane 
B)  Hinge 
C)  Ball- and- socket 
D)  Suture

Exam 41: Action and Support: the Muscles and Skeleton

A muscle fiber generates maximum contractile force when

What is the function of the sarcoplasmic reticulum?

Which of the following is TRUE with regard to the sliding filament mechanism of muscle contraction?

Describe some of the important functions of the vertebrate endoskeleton.

If a doctor tells a patient that he has broken an axial bone, to which of these bones would the doctor be referring? A) Radius B) Ilium C) Clavicle D) Vertebra E) Fibula

Arrange these muscle tissue groupings in order, from most inclusive to least inclusive: sarcomere, motor unit, thick and thin filaments, myofibril, muscle fiber.

Which molecule contains a binding site for the attachment of myosin heads?

Bones store calcium and

The type of ion found in high concentrations in the sarcoplasmic reticulum is .

When a muscle fiber receives an action potential from a neuron, how many sarcomeres in the fiber contract?

Osteoporosis is the

What is the function of troponin and tropomyosin during skeletal muscle contraction?

Both smooth and cardiac muscle fibers

Cartilage primarily consists of

Some joints, such as those joining the bones of the skull, are immobile and do not allow the two bones involved to move.

What might be a major disadvantage of having a ball- and- socket joint, rather than a hinge joint, in the human knee?

Skeletal muscle appears striped because of the

Bone- forming cells are known as

This figure illustrates what type of joint?

An Introduction to Life on Earth

Atoms, Molecules, and Life

Biological Molecules

Cell Structure and Function

Cell Membrane Structure and Function

Energy Flow in the Life of a Cell

Capturing Solar Energy: Photosynthesis

Harvesting Energy: Glycolysis and Cellular Respiration

Cellular Reproduction

Meiosis: the Basis of Sexual Reproduction

Patterns of Inheritance

Dna: the Molecule of Heredity

Gene Expression and Regulation

Biotechnology

Principles of Evolution

How Populations Evolve

The Origin of Species

The History of Life

Systematics: Seeking Order Amid Diversity

The Diversity of Prokaryotes and Viruses

The Diversity of Protists

The Diversity of Plants

The Diversity of Fungi

Animal Diversity I: Invertebrates

Animal Diversity II: Vertebrates

Animal Behavior

Population Growth and Regulation

Community Interactions

Energy Flow and Nutrient Cycling in Ecosystems

Earths Diverse Ecosystems

Conserving Earths Biodiversity

Homeostasis and the Organization of the Animal Body

Circulation

Respiration

Nutrition and Digestion

The Urinary System

Defenses Against Disease

Chemical Control of the Animal Body: the Endocrine System

The Nervous System

The Senses

Animal Reproduction

Animal Development

Plant Anatomy and Nutrient Transport

Plant Reproduction and Development

Plant Responses to the Environment

Filters