Question 1

Prions induce normal Prp on the surface of brain cells to misfold into a(n) insoluble form and cause brain damage. 
____________________

Accepted Answer

A) True 
 B)False  False

Question 2

The bacterium that causes botulism disease is harmless until it:

Accepted Answer

A)  is infected by prions. 
B)  is infected by lytic bacteria. 
C)  is irradiated by UV radiation. 
D)  contains a certain prophage DNA. 
E)  is infected by certain retroviruses. 
A)  is infected by prions. 
B)  is infected by lytic bacteria. 
C)  is irradiated by UV radiation. 
D)  contains a certain prophage DNA. 
E)  is infected by certain retroviruses. D

Question 3

What is the difference between a viral lytic cycle and a viral lysogenic cycle?

Accepted Answer

In a lytic infection the virus destroys the host cell. The virus takes over the host cell's metabolism and forces the host cell to replicate viral particles. Lytic infections result in cell lysis and death. 
In lysogenic infections, temperate viruses integrate into the host DNA. The integrated virus is called a provirus. When the bacterial DNA replicates, the provirus DNA replicates with the host cell genome. Temperate viruses revert to lytic cycles under stress conditions.

Question 4

Which hypothesis asserts that viruses are remnants of cellular organisms and evolved from small cells that were parasites in larger cells?

Accepted Answer

A)  escape hypothesis 
B)  virus-first hypothesis 
C)  regressive hypothesis 
D)  progressive hypothesis 
E)  degenerative hypothesis 
A)  escape hypothesis 
B)  virus-first hypothesis 
C)  regressive hypothesis 
D)  progressive hypothesis 
E)  degenerative hypothesis

Question 5

Which statement about viruses is FALSE ?

Accepted Answer

A)  Viruses are not cellular. 
B)  Viruses can manufacture proteins. 
C)  Viruses cannot carry on metabolic activities. 
D)  Viruses can only replicate by infecting other cells. 
E)  Viruses have a protective protein coat called a capsid. 
A)  Viruses are not cellular. 
B)  Viruses can manufacture proteins. 
C)  Viruses cannot carry on metabolic activities. 
D)  Viruses can only replicate by infecting other cells. 
E)  Viruses have a protective protein coat called a capsid.

Question 6

Dr. Stanley Prusiner concluded that the infective agent of CJD was not a(n) virus because it was not sensitive to radiation which mutates nucleic acids. 
____________________

Accepted Answer

A) True 
 B)False

Question 7

Why can measles virus and poxvirus infect many human tissues and influenza virus can infect only one type of tissue?

Accepted Answer

Measles virus and poxvirus hav

Question 8

The genome of most plant viruses consists of what kind of RNA?

Accepted Answer

A)  rRNA 
B)  mRNA 
C)  ssRNA 
D)  dsRNA 
E)  SRP RNA 
A)  rRNA 
B)  mRNA 
C)  ssRNA 
D)  dsRNA 
E)  SRP RNA

Question 9

A virus consists of a DNA or RNA core surrounded by a(n) envelope . 
____________________

Accepted Answer

A) True 
 B)False

Question 10

Bacteriophages attach to the cell walls of bacteria by envelope proteins. ____________________

Accepted Answer

A) True 
 B)False

Question 11

Which characteristic defines a virus?

Accepted Answer

A)  Viruses cannot replicate. 
B)  Viruses cannot metabolize. 
C)  Viruses contain both RNA and DNA. 
D)  Viruses have various morphologies. 
E)  Viruses are very tiny cells with nuclei. 
A)  Viruses cannot replicate. 
B)  Viruses cannot metabolize. 
C)  Viruses contain both RNA and DNA. 
D)  Viruses have various morphologies. 
E)  Viruses are very tiny cells with nuclei.

Question 12

What is the protein coat of a virus called?

Accepted Answer

A)  envelope 
B)  capsule 
C)  capsid 
D)  phage 
E)  pilus 
A)  envelope 
B)  capsule 
C)  capsid 
D)  phage 
E)  pilus

Question 13

Which has an unusual characteristic in that their circular DNA does not have genes for making the proteins needed to replicate and produce new viruses?

Accepted Answer

A)  viroid 
B)  retroviruses 
C)  bacteriophages 
D)  pandoraviruses 
E)  polydnaviruses 
A)  viroid 
B)  retroviruses 
C)  bacteriophages 
D)  pandoraviruses 
E)  polydnaviruses

Question 14

Figure 24-1d   Refer to the accompanying figure. What is the function of the structure labeled as 3?

Accepted Answer

A)  replication 
B)  locomotion 
C)  mate recognition 
D)  attachment to a host cell 
E)  to take over host cell mechanisms 
A)  replication 
B)  locomotion 
C)  mate recognition 
D)  attachment to a host cell 
E)  to take over host cell mechanisms

Question 15

How do retroviruses differ from other RNA viruses?

Accepted Answer

A)  Retroviruses have a unique capsid shape. 
B)  Retroviruses lytically destroy their hosts. 
C)  Retroviruses have a unique infection technique of their host cells. 
D)  Retroviruses have a capsid composed of protein and carbohydrates. 
E)  Retroviruses have reverse transcriptase instead of RNA-dependent RNA polymerase. 
A)  Retroviruses have a unique capsid shape. 
B)  Retroviruses lytically destroy their hosts. 
C)  Retroviruses have a unique infection technique of their host cells. 
D)  Retroviruses have a capsid composed of protein and carbohydrates. 
E)  Retroviruses have reverse transcriptase instead of RNA-dependent RNA polymerase.

Question 16

Compare and contrast the three hypotheses which explain the evolution of viruses

Accepted Answer

CONCEPTS TO CONSIDER : 
According to the

Question 17

The five stages of a lytic infection are attachment, penetration, __________, assembly, and release.

Accepted Answer

A)  lysis 
B)  prophage 
C)  replication 
D)  lysogenesis 
E)  transduction 
A)  lysis 
B)  prophage 
C)  replication 
D)  lysogenesis 
E)  transduction

Question 18

At what stage of the lysogenic cycle would a prophage appear?

Accepted Answer

A)  penetration 
B)  integration 
C)  attachment 
D)  replication 
E)  assembly 
A)  penetration 
B)  integration 
C)  attachment 
D)  replication 
E)  assembly

Question 19

Bacteriophages decrease food safety . 
____________________

Accepted Answer

A) True 
 B)False

Question 20

At what stage of a lytic infection are phage components put together to make new viruses?

Accepted Answer

A)  replication and synthesis 
B)  penetration 
C)  attachment 
D)  assembly 
E)  release 
A)  replication and synthesis 
B)  penetration 
C)  attachment 
D)  assembly 
E)  release

Exam 24: Viruses and Subviral Agents

Prions induce normal Prp on the surface of brain cells to misfold into a(n) insoluble form and cause brain damage. ____________________

The bacterium that causes botulism disease is harmless until it:

What is the difference between a viral lytic cycle and a viral lysogenic cycle?

Which hypothesis asserts that viruses are remnants of cellular organisms and evolved from small cells that were parasites in larger cells?

Which statement about viruses is FALSE ?

Dr. Stanley Prusiner concluded that the infective agent of CJD was not a(n) virus because it was not sensitive to radiation which mutates nucleic acids. ____________________

Why can measles virus and poxvirus infect many human tissues and influenza virus can infect only one type of tissue?

The genome of most plant viruses consists of what kind of RNA?

A virus consists of a DNA or RNA core surrounded by a(n) envelope . ____________________

Bacteriophages attach to the cell walls of bacteria by envelope proteins. ____________________

Which characteristic defines a virus?

What is the protein coat of a virus called?

Which has an unusual characteristic in that their circular DNA does not have genes for making the proteins needed to replicate and produce new viruses?

Figure 24-1d Refer to the accompanying figure. What is the function of the structure labeled as 3?

How do retroviruses differ from other RNA viruses?

Compare and contrast the three hypotheses which explain the evolution of viruses

The five stages of a lytic infection are attachment, penetration, __________, assembly, and release.

At what stage of the lysogenic cycle would a prophage appear?

Bacteriophages decrease food safety . ____________________

At what stage of a lytic infection are phage components put together to make new viruses?

A View of Life

Atoms and Molecules the Chemical Basis of Life

The Chemistry of Life Organic Compounds

Organization of the Cell

Biological Membranes

Cell Communication

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

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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