Question 1

Which of the following is the best explanation for the fact that most transduction pathways have multiple steps?

Accepted Answer

A) Most of the steps were already in place because they are steps in other pathways. 
B) Multiple steps in a pathway require the least amount of ATP. 
C) Multiple steps provide for greater possible amplification of a signal. 
D) Each individual step can remove excess phosphate groups from the cytoplasm. 
E) Each step can be activated by several G proteins simultaneously. 
A) Most of the steps were already in place because they are steps in other pathways. 
B) Multiple steps in a pathway require the least amount of ATP. 
C) Multiple steps provide for greater possible amplification of a signal. 
D) Each individual step can remove excess phosphate groups from the cytoplasm. 
E) Each step can be activated by several G proteins simultaneously.

Question 2

A molecule that specifically binds to another molecule (often a larger one)is known as a(n)

Accepted Answer

A) ligand. 
B) receptor. 
C) transcription factor. 
D) activator. 
E) scaffolding protein. 
A) ligand. 
B) receptor. 
C) transcription factor. 
D) activator. 
E) scaffolding protein.

Question 3

Sutherland's research showed that cell-to-cell communication can be divided into three distinct parts that follow a particular sequence.In order from first to last,these are

Accepted Answer

A) transduction, response, reception. 
B) reception, transduction, response. 
C) transcription, translation, response. 
D) transduction, transcription, translation. 
E) first messenger, second messenger, product. 
A) transduction, response, reception. 
B) reception, transduction, response. 
C) transcription, translation, response. 
D) transduction, transcription, translation. 
E) first messenger, second messenger, product.

Question 4

Which of the following poses the best evidence that cell-signaling pathways evolved early in the history of life?

Accepted Answer

A) Cell-signaling pathways are seen in "primitive" cells such as bacteria and yeast. 
B) Bacteria and yeast cells may undertake quorum sensing. 
C) Signal transduction molecules identified in distantly related organisms are similar. 
D) Most signals in all types of cells are received by cell surface receptors. 
E) Signals in bacteria are hydrophobic and do not require a cell surface receptor. 
A) Cell-signaling pathways are seen in "primitive" cells such as bacteria and yeast. 
B) Bacteria and yeast cells may undertake quorum sensing. 
C) Signal transduction molecules identified in distantly related organisms are similar. 
D) Most signals in all types of cells are received by cell surface receptors. 
E) Signals in bacteria are hydrophobic and do not require a cell surface receptor.

Question 5

What explains the increased concentration of Ca²⁺ in the ER?

Accepted Answer

A) Calcium ions are actively imported from the cytoplasm into the ER. 
B) Calcium concentration is kept low in the cytoplasm because of its high usage level. 
C) Calcium cannot enter the plasma membrane through ion channels. 
D) Calcium levels in the blood or other body fluids are extremely low. 
E) The Ca ions are recycled from other molecules in the ER. 
A) Calcium ions are actively imported from the cytoplasm into the ER. 
B) Calcium concentration is kept low in the cytoplasm because of its high usage level. 
C) Calcium cannot enter the plasma membrane through ion channels. 
D) Calcium levels in the blood or other body fluids are extremely low. 
E) The Ca ions are recycled from other molecules in the ER.

Exam 11: Cell Communication

Which of the following is the best explanation for the fact that most transduction pathways have multiple steps?

A molecule that specifically binds to another molecule (often a larger one)is known as a(n)

Sutherland's research showed that cell-to-cell communication can be divided into three distinct parts that follow a particular sequence.In order from first to last,these are

Which of the following poses the best evidence that cell-signaling pathways evolved early in the history of life?

What explains the increased concentration of Ca²⁺ in the ER?

Introduction: Evolution and Themes of Biology

The Chemical Context of Life

Water and Life

Carbon and the Molecular Diversity of Life

The Structure and Function of Large Biological Molecules

A Tour of the Cell

Membrane Structure and Function

An Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

From Gene to Protein

Regulation of Gene Expression

Viruses

DNA Tools and Biotechnology

Genomes and Their Evolution

Descent with Modification: A Darwinian View of Life

The Evolution of Populations

The Origin of Species

The History of Life on Earth

Phylogeny and the Tree of Life

Bacteria and Archaea

Protists

Plant Diversity I: How Plants Colonized Land

Plant Diversity II: The Evolution of Seed Plants

Fungi

An Overview of Animal Diversity

An Introduction to Invertebrates

The Origin and Evolution of Vertebrates

Plant Structure,Growth,and Development

Resource Acquisition and Transport in Vascular Plants

Soil and Plant Nutrition

Angiosperm Reproduction and Biotechnology

Plant Responses to Internal and External Signals

Basic Principles of Animal Form and Function

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Osmoregulation and Excretion

Hormones and the Endocrine System

Animal Reproduction

Animal Development

Neurons,Synapses,and Signalling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behaviour

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

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