Question 1

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 2

Under which of the following situations would receptor down-regulation most likely occur?

Accepted Answer

A)  The number of G proteins is too high. 
B)  The concentration of a hormone is too high. 
C)  The cell is unable to manufacture cyclic AMP. 
D)  The concentration of a neurotransmitter is too low. 
E)  The number of receptors in the plasma membrane is too low. 
A)  The number of G proteins is too high. 
B)  The concentration of a hormone is too high. 
C)  The cell is unable to manufacture cyclic AMP. 
D)  The concentration of a neurotransmitter is too low. 
E)  The number of receptors in the plasma membrane is too low.

Question 3

In the phospholipase C signal transduction pathway, which two second messengers are produced?

Accepted Answer

A)  IP3 and DAG 
B)  PIP2 and IP3 
C)  cAMP and IP3 
D)  phospholipase C and protein kinase A 
E)  phospholipase C and G protein 
A)  IP3 and DAG 
B)  PIP2 and IP3 
C)  cAMP and IP3 
D)  phospholipase C and protein kinase A 
E)  phospholipase C and G protein

Question 4

Where are calcium ions stored before a signaling pathway releases them into the cytosol?

Accepted Answer

A)  nucleus 
B)  ribosome 
C)  lysosome 
D)  plasma membrane 
E)  endoplasmic reticulum 
A)  nucleus 
B)  ribosome 
C)  lysosome 
D)  plasma membrane 
E)  endoplasmic reticulum

Question 5

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

Accepted Answer

A)  It function is 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 function is 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.

Question 6

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 7

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 8

What is typically the result of receptor up-regulation?

Accepted Answer

A)  A hormone's signal is amplified. 
B)  The number of receptors decreases. 
C)  The sensitivity of a cell to a hormone decreases. 
D)  The number of genes that code for a receptor increases. 
E)  The concentration of hormone molecules in the blood increases. 
A)  A hormone's signal is amplified. 
B)  The number of receptors decreases. 
C)  The sensitivity of a cell to a hormone decreases. 
D)  The number of genes that code for a receptor increases. 
E)  The concentration of hormone molecules in the blood increases.

Question 9

Most intracellular receptors are what type of protein?

Accepted Answer

A)  DNA 
B)  steroids 
C)  enzymes 
D)  neurotransmitters 
E)  transcription factors 
A)  DNA 
B)  steroids 
C)  enzymes 
D)  neurotransmitters 
E)  transcription factors

Exam 6: Cell Communication

Which statement about receptors is false ?

Under which of the following situations would receptor down-regulation most likely occur?

In the phospholipase C signal transduction pathway, which two second messengers are produced?

Where are calcium ions stored before a signaling pathway releases them into the cytosol?

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

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

What can happen when GABA binds to its receptor?

What is typically the result of receptor up-regulation?

Most intracellular receptors are what type of protein?

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

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