Question 1

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

Question 2

What happens to an astronaut who spends 2 months in the weightless environment of a space capsule?

Accepted Answer

A)  Bone density increases and muscle mass increases. 
B)  Bone density decreases and muscle mass increases. 
C)  Bone density decreases and muscle mass decreases. 
D)  Bone density increases and muscle mass decreases. 
A)  Bone density increases and muscle mass increases. 
B)  Bone density decreases and muscle mass increases. 
C)  Bone density decreases and muscle mass decreases. 
D)  Bone density increases and muscle mass decreases.

Question 3

What two types of contractions do smooth muscles perform?

Accepted Answer

slow, sustained cont

Question 4

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 5

What is the major disadvantage of an exoskeleton?

Accepted Answer

A)  It does not protect the internal organs. 
B)  It must be periodically shed for growth to occur. 
C)  It hardens only after an extended exposure to air. 
D)  It does not provide effective support for muscles. 
A)  It does not protect the internal organs. 
B)  It must be periodically shed for growth to occur. 
C)  It hardens only after an extended exposure to air. 
D)  It does not provide effective support for muscles.

Question 6

Cartilage is composed of specialized cells called

Accepted Answer

A)  chondrocytes. 
B)  osteoblasts. 
C)  osteoclasts. 
D)  erythrocytes. 
E)  platelets. 
A)  chondrocytes. 
B)  osteoblasts. 
C)  osteoclasts. 
D)  erythrocytes. 
E)  platelets.

Question 7

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

Question 8

Cartilage is well supplied with blood vessels.

Accepted Answer

A) True 
 B)False

Question 9

The site of communication between a neuron and a muscle fiber is called a

Accepted Answer

A)  neuromuscular junction. 
B)  sarcomere. 
C)  myofibril. 
D)  Z disc. 
A)  neuromuscular junction. 
B)  sarcomere. 
C)  myofibril. 
D)  Z disc.

Question 10

Calcium binding to ___________initiates skeletal muscle contraction.

Accepted Answer

A)  troponin 
B)  tropomyosin 
C)  actin 
D)  myosin 
A)  troponin 
B)  tropomyosin 
C)  actin 
D)  myosin

Question 11

Action potentials stimulate the sarcoplasmic reticulum to release chloride ions into the muscle cell.

Accepted Answer

A) True 
 B)False

Question 12

The end of a skeletal muscle that is attached to a stationary, fixed bone is the origin. The end of a skeletal muscle that is attached to a movable bone is called the

Accepted Answer

A)  extensor. 
B)  hinge. 
C)  joint. 
D)  insertion. 
E)  flexor. 
A)  extensor. 
B)  hinge. 
C)  joint. 
D)  insertion. 
E)  flexor.

Question 13

In cardiac muscle

Accepted Answer

A)  calcium enters the cell from storage chambers called intercalated discs. 
B)  an action potential spreads throughout the Z discs. 
C)  intercalated discs connect the muscle fibers together. 
D)  potassium is released from the sarcoplasmic reticulum. 
A)  calcium enters the cell from storage chambers called intercalated discs. 
B)  an action potential spreads throughout the Z discs. 
C)  intercalated discs connect the muscle fibers together. 
D)  potassium is released from the sarcoplasmic reticulum.

Question 14

In a hinge joint

Accepted Answer

A)  motion occurs when gravity pulls on the insertion. 
B)  movement can occur only in two dimensions. 
C)  the flexor and the extensor must contract at the same time. 
D)  movement in three dimensions is possible. 
E)  an extensor muscle rotates the bones. 
A)  motion occurs when gravity pulls on the insertion. 
B)  movement can occur only in two dimensions. 
C)  the flexor and the extensor must contract at the same time. 
D)  movement in three dimensions is possible. 
E)  an extensor muscle rotates the bones.

Question 15

Osteoporosis is the

Accepted Answer

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

Question 16

Protein bands that connect sarcomeres are called

Accepted Answer

A)  myofibrils. 
B)  troponins. 
C)  T tubules. 
D)  Z discs. 
A)  myofibrils. 
B)  troponins. 
C)  T tubules. 
D)  Z discs.

Question 17

Which of these animals is correctly matched with its type of skeleton?

Accepted Answer

A)  Earthworm/endoskeleton 
B)  Shark/hydroskeleton 
C)  Bird/exoskeleton 
D)  Mayfly/hydroskeleton 
E)  Lobster/exoskeleton 
A)  Earthworm/endoskeleton 
B)  Shark/hydroskeleton 
C)  Bird/exoskeleton 
D)  Mayfly/hydroskeleton 
E)  Lobster/exoskeleton

Question 18

A joint that is movable in only two dimensions, such as the elbow, is called a____________joint.

Accepted Answer

The answer of A joint that is movable in only...

Question 19

It is possible to remove calcium from compact bone by soaking the bone in vinegar for an extended period of time. Once the calcium is gone, the bone should be

Accepted Answer

A)  about half the size as before soaking. 
B)  extremely flexible. 
C)  completely dissolved. 
D)  more rigid and inflexible. 
A)  about half the size as before soaking. 
B)  extremely flexible. 
C)  completely dissolved. 
D)  more rigid and inflexible.

Question 20

A muscle fiber generates maximum contractile force when

Accepted Answer

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

Exam 41: Action and Support: the Muscles and Skeleton

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

What happens to an astronaut who spends 2 months in the weightless environment of a space capsule?

What two types of contractions do smooth muscles perform?

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

What is the major disadvantage of an exoskeleton?

Cartilage is composed of specialized cells called

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

Cartilage is well supplied with blood vessels.

The site of communication between a neuron and a muscle fiber is called a

Calcium binding to ___________initiates skeletal muscle contraction.

Action potentials stimulate the sarcoplasmic reticulum to release chloride ions into the muscle cell.

The end of a skeletal muscle that is attached to a stationary, fixed bone is the origin. The end of a skeletal muscle that is attached to a movable bone is called the

In cardiac muscle

In a hinge joint

Osteoporosis is the

Protein bands that connect sarcomeres are called

Which of these animals is correctly matched with its type of skeleton?

A joint that is movable in only two dimensions, such as the elbow, is called a____________joint.

It is possible to remove calcium from compact bone by soaking the bone in vinegar for an extended period of time. Once the calcium is gone, the bone should be

A muscle fiber generates maximum contractile force when

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

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