Question 1

What type of protein can transduce a signal in two directions?

Accepted Answer

A)  Integrins 
B)  G proteins 
C)  Ras proteins 
D)  Scaffold proteins 
E)  Phosphorylated proteins 
A)  Integrins 
B)  G proteins 
C)  Ras proteins 
D)  Scaffold proteins 
E)  Phosphorylated proteins A

Question 2

Which local regulator is stored in cells of the immune system and released during an allergic reaction?

Accepted Answer

A)  Histamine 
B)  Nitric oxide 
C)  A growth factor 
D)  A prostaglandin 
E)  A neurotransmitter 
A)  Histamine 
B)  Nitric oxide 
C)  A growth factor 
D)  A prostaglandin 
E)  A neurotransmitter A

Question 3

A receptor on the cell surface usually has several domains. What is the function of the external domain?

Accepted Answer

A)  It functions as an enzyme. 
B)  It attaches the receptor to the DNA. 
C)  It holds the receptor within the membrane. 
D)  It transmits the signal to the inside of the cell. 
E)  It is the docking site for a signaling molecule. 
A)  It functions as an enzyme. 
B)  It attaches the receptor to the DNA. 
C)  It holds the receptor within the membrane. 
D)  It transmits the signal to the inside of the cell. 
E)  It is the docking site for a signaling molecule. E

Question 4

Which list describes the correct sequence of events involved in cell signaling?

Accepted Answer

A)  Signal transduction, reception, signal transmission, response 
B)  Response, signal transduction, signal transmission, reception 
C)  Signal transmission, signal transduction, reception, response 
D)  Reception, signal transmission, response, signal transduction 
E)  Signal transmission, reception, signal transduction, response 
A)  Signal transduction, reception, signal transmission, response 
B)  Response, signal transduction, signal transmission, reception 
C)  Signal transmission, signal transduction, reception, response 
D)  Reception, signal transmission, response, signal transduction 
E)  Signal transmission, reception, signal transduction, response

Question 5

The gas ethylene is a plant hormone that regulates a variety of processes, including seed germination and ripening of fruit.

Accepted Answer

A) True 
 B)False

Question 6

Phosphodiesterase catalyzes the conversion of

Accepted Answer

A)  IP3 to PIP2. 
B)  GDP to GTP. 
C)  cAMP to AMP. 
D)  calcium to calcium-calmodulin. 
E)  a protein to a phosphorylated protein. 
A)  IP3 to PIP2. 
B)  GDP to GTP. 
C)  cAMP to AMP. 
D)  calcium to calcium-calmodulin. 
E)  a protein to a phosphorylated protein.

Question 7

G protein-linked receptors are transmembrane proteins with a binding site for a signaling molecule outside the cell and a neuron component inside the cell.

Accepted Answer

A) True 
 B)False

Question 8

Suppose that acetylcholine binds its receptor on the surface of a muscle cell. What happens next?

Accepted Answer

A)  A sodium gate opens. 
B)  G protein is activated. 
C)  Tyrosine is phosphorylated. 
D)  Tyrosine kinase is activated. 
E)  A neurotransmitter crosses the synapse. 
A)  A sodium gate opens. 
B)  G protein is activated. 
C)  Tyrosine is phosphorylated. 
D)  Tyrosine kinase is activated. 
E)  A neurotransmitter crosses the synapse.

Question 9

Which is a major group of enzyme-linked receptors?

Accepted Answer

A)  G proteins 
B)  Ion channels 
C)  Tyrosine kinases 
D)  Phospholipases 
E)  Adenylyl cyclases 
A)  G proteins 
B)  Ion channels 
C)  Tyrosine kinases 
D)  Phospholipases 
E)  Adenylyl cyclases

Question 10

Which molecule is a first messenger but not a second messenger?

Accepted Answer

A)  G protein 
B)  Cyclic AMP 
C)  Acetylcholine 
D)  Protein kinase 
E)  Adenylyl cyclase 
A)  G protein 
B)  Cyclic AMP 
C)  Acetylcholine 
D)  Protein kinase 
E)  Adenylyl cyclase

Question 11

What can happen when GABA binds to its receptor?

Accepted Answer

A)  Neural signaling is inhibited. 
B)  Sodium ions enter the cell. 
C)  New signals are transmitted. 
D)  Muscle contraction is stimulated. 
E)  Enzyme-linked receptors are activated. 
A)  Neural signaling is inhibited. 
B)  Sodium ions enter the cell. 
C)  New signals are transmitted. 
D)  Muscle contraction is stimulated. 
E)  Enzyme-linked receptors are activated.

Question 12

Briefly, describe three examples of how cells respond to signals. Describe two possible mechanisms of signal termination.

Accepted Answer

Concepts to Consider: Regulation of ion

Question 13

Which is a part of a signal transduction pathway that enables vision in dim light in vertebrates?

Accepted Answer

A)  Acetylcholine 
B)  Histamine 
C)  Brassinosteroids 
D)  Rhodopsin 
E)  Phosphorylation 
A)  Acetylcholine 
B)  Histamine 
C)  Brassinosteroids 
D)  Rhodopsin 
E)  Phosphorylation

Question 14

Typically, the gate of an ion channel remains closed until a(n) ____ binds to the receptor.

Accepted Answer

A)  ligand 
B)  enzyme 
C)  G protein 
D)  target cell 
E)  first messenger 
A)  ligand 
B)  enzyme 
C)  G protein 
D)  target cell 
E)  first messenger

Question 15

How are hormones produced by endocrine glands typically transported to target cells?

Accepted Answer

A)  By the blood 
B)  Through the air 
C)  Across a synapse 
D)  Via direct contact 
E)  Through interstitial fluid 
A)  By the blood 
B)  Through the air 
C)  Across a synapse 
D)  Via direct contact 
E)  Through interstitial fluid

Question 16

When a signaling molecule binds to a G protein-linked receptor, the ligand-receptor complex associates with GDP protein and causes GDP to be replaced by GTP.  __________________

Accepted Answer

A) True 
 B)False

Question 17

When food is scarce, the amoeba-like cellular slime mold, Dictyostelium , secretes which compound?

Accepted Answer

A)  Glucocorticoid 
B)  Cyclic adenosine monophosphate 
C)  Estrogen 
D)  Insulin 
E)  Glucagon 
A)  Glucocorticoid 
B)  Cyclic adenosine monophosphate 
C)  Estrogen 
D)  Insulin 
E)  Glucagon

Question 18

What is meant by signal amplification? Provide two examples.

Accepted Answer

Signal amplification occurs when a signa

Question 19

Which statement about receptors is false ?

Accepted Answer

A)  They are highly selective. 
B)  They are also called ligands. 
C)  They are proteins or glycoproteins. 
D)  They are found inside the cell and on the cell surface. 
E)  They are activated by binding to a signaling molecule. 
A)  They are highly selective. 
B)  They are also called ligands. 
C)  They are proteins or glycoproteins. 
D)  They are found inside the cell and on the cell surface. 
E)  They are activated by binding to a signaling molecule.

Question 20

The process of receiving an incoming signal is known as _______.

Accepted Answer

A)  signal transduction 
B)  receptor 
C)  reception 
D)  signal transmission 
E)  response 
A)  signal transduction 
B)  receptor 
C)  reception 
D)  signal transmission 
E)  response

Exam 6: Cell Communication

What type of protein can transduce a signal in two directions?

Which local regulator is stored in cells of the immune system and released during an allergic reaction?

A receptor on the cell surface usually has several domains. What is the function of the external domain?

Which list describes the correct sequence of events involved in cell signaling?

The gas ethylene is a plant hormone that regulates a variety of processes, including seed germination and ripening of fruit.

Phosphodiesterase catalyzes the conversion of

G protein-linked receptors are transmembrane proteins with a binding site for a signaling molecule outside the cell and a neuron component inside the cell.

Suppose that acetylcholine binds its receptor on the surface of a muscle cell. What happens next?

Which is a major group of enzyme-linked receptors?

Which molecule is a first messenger but not a second messenger?

What can happen when GABA binds to its receptor?

Briefly, describe three examples of how cells respond to signals. Describe two possible mechanisms of signal termination.

Which is a part of a signal transduction pathway that enables vision in dim light in vertebrates?

Typically, the gate of an ion channel remains closed until a(n) ____ binds to the receptor.

How are hormones produced by endocrine glands typically transported to target cells?

When a signaling molecule binds to a G protein-linked receptor, the ligand-receptor complex associates with GDP protein and causes GDP to be replaced by GTP. __________________

When food is scarce, the amoeba-like cellular slime mold, Dictyostelium , secretes which compound?

What is meant by signal amplification? Provide two examples.

Which statement about receptors is false ?

The process of receiving an incoming signal is known as _______.

A View of Life

Atoms and Molecules: the Chemical Basis of Life

The Chemistry of Life: Organic Compounds

Organization of the Cell

Biological Membranes

Energy and Metabolism

How Cells Make Atp: Energy-Releasing Pathways

Photosynthesis: Capturing Light Energy

Chromosomes, Mitosis, and Meiosis

The Basic Principles of Heredity

DNA: The Carrier of Genetic Information

Gene Expression

Gene Regulation

DNA Technology and Genomics

Human Genetics and the Human Genome

Developmental Genetics

Introduction to Darwinian Evolution

Evolutionary Change in Populations

Speciation and Macroevolution

The Origin and Evolutionary History of Life

The Evolution of Primates

Understanding Diversity: Systematics

Viruses and Subviral Agents

Bacteria and Archaea

Protists

Seedless Plants

Seed Plants

The Fungi

An Introduction to Animal Diversity

Sponges, Cnidarians, Ctenophores, and Protostomes

The Deuterostomes

Plant Structure, Growth, and Development

Leaf Structure and Function

Stem Structure and Transport

Roots and Mineral Nutrition

Reproduction in Flowering Plants

Plant Developmental Responses to External and Internal Signals

Animal Structure and Function: an Introduction

Protection, Support, and Movement

Neural Signaling

Neural Regulation

Sensory Systems

Internal Transport

The Immune System: Internal Defense

Gas Exchange

Processing Food and Nutrition

Osmoregulation and Disposal of Metabolic Wastes

Endocrine Regulation

Reproduction

Animal Development

Animal Behavior

Introduction to Ecology: Population Ecology

Community Ecology

Ecosystems and the Biosphere

Ecology and the Geography of Life

Biological Diversity and Conservation Biology

Filters