Question 1

In the context of biogeochemical cycling, explain the role of bacteriophages and their impact on carbon cycling in the oceans.

Accepted Answer

Viruses that infect bacteria and lyse them are an integral part to cycling carbon in a system such as an ocean, where bacteria are abundant. This cell lysis frees up carbon stored in the cells as well as their cellular debris, which both provide a system with usable carbon substrates for others to use and proliferate.

Question 2

Viral replication is

Accepted Answer

A)  dependent on the cell's chromosomes but independent of the cell itself. 
B)  independent of the cell's chromosomes but dependent on the cell itself. 
C)  independent of both the cell's chromosomes and the cell itself (although the cell does provide a convenient matrix for replication). 
D)  dependent on both the cell's chromosomes and the cell itself. 
A)  dependent on the cell's chromosomes but independent of the cell itself. 
B)  independent of the cell's chromosomes but dependent on the cell itself. 
C)  independent of both the cell's chromosomes and the cell itself (although the cell does provide a convenient matrix for replication). 
D)  dependent on both the cell's chromosomes and the cell itself. B

Question 3

Viral size is generally measured in

Accepted Answer

A)  micrometers. 
B)  picometers. 
C)  centimeters. 
D)  nanometers. 
A)  micrometers. 
B)  picometers. 
C)  centimeters. 
D)  nanometers. D

Question 4

Plant viruses can be difficult to work with because

Accepted Answer

A)  plant viruses often require a break in the plant cell wall to initiate infection. 
B)  their study sometimes requires the use of the whole plant. 
C)  plants typically grow much slower than bacteria. 
D)  All of the above are factors. 
A)  plant viruses often require a break in the plant cell wall to initiate infection. 
B)  their study sometimes requires the use of the whole plant. 
C)  plants typically grow much slower than bacteria. 
D)  All of the above are factors.

Question 5

Viral proteins are categorized as early and late. Early proteins are_________ , while late proteins include_________ .

Accepted Answer

necessary for replic

Question 6

A viroid

Accepted Answer

A)  is a small, circular ssRNA molecule. 
B)  lacks protein- encoding genes. 
C)  lacks a capsid. 
D)  is characterized by all of the above. 
A)  is a small, circular ssRNA molecule. 
B)  lacks protein- encoding genes. 
C)  lacks a capsid. 
D)  is characterized by all of the above.

Question 7

Explain the concept of a persistent infection in terms of a virus- infected cell.

Accepted Answer

Persistent viral infections occur when t

Question 8

Using T4 virions as a model, explain the concept of circular permutation.

Accepted Answer

A linear concatemer is first formed afte

Question 9

The virus repressor protein

Accepted Answer

A)  has different actions in different situations. 
B)  does not control the prophage's lytic genes but does control the incoming genomes of the same virus. 
C)  controls the prophage's lytic genes but not the incoming genomes of the same virus. 
D)  controls both the lytic genes on the prophage and prevents an incoming virus of the same type. 
A)  has different actions in different situations. 
B)  does not control the prophage's lytic genes but does control the incoming genomes of the same virus. 
C)  controls the prophage's lytic genes but not the incoming genomes of the same virus. 
D)  controls both the lytic genes on the prophage and prevents an incoming virus of the same type.

Question 10

Which of the following are the hosts for most enveloped viruses?

Accepted Answer

A)  Archaea 
B)  animals 
C)  Bacteria 
D)  fungi 
A)  Archaea 
B)  animals 
C)  Bacteria 
D)  fungi

Question 11

Currently there is no formal system of viral taxonomy, although several systems are presently being developed.

Accepted Answer

A) True 
 B)False

Question 12

When a virus enters a host cell in which it can replicate, the process is called a(n)_________ .

Accepted Answer

The answer of When a virus enters a host cell...

Question 13

Temperate viruses can enter into either a lytic or lysogenic cycle.

Accepted Answer

A) True 
 B)False

Question 14

The primer for retrovirus reverse transcription is a specific

Accepted Answer

A)  nuclear tRNA. 
B)  nuclear tDNA. 
C)  tRNA encoded by the cell. 
D)  tRNA encoded by the virus. 
A)  nuclear tRNA. 
B)  nuclear tDNA. 
C)  tRNA encoded by the cell. 
D)  tRNA encoded by the virus.

Question 15

Two chemical modifications of viral DNA that work to avoid host restriction mechanisms are_________ and _________.

Accepted Answer

glucosylat

Question 16

Why is uncoating a step in the replication cycle of some animal viruses?

Accepted Answer

The genome is freely available

Question 17

When packaged in the virion, the complete complex of nucleic acid and protein is known as the virus

Accepted Answer

A)  concatemer. 
B)  nucleocapsid. 
C)  envelope. 
D)  capsid. 
A)  concatemer. 
B)  nucleocapsid. 
C)  envelope. 
D)  capsid.

Question 18

Regarding the viral membrane in an enveloped virus, the lipids are derived from the_________, and the proteins are encoded by __________ .

Accepted Answer

host's cel

Question 19

Avirulent prions consist largely of_________ , whereas pathogenic prions have more
regions.

Accepted Answer

a- helices

Question 20

Animal viruses are more easily lysed compared to prokaryotic cells, because animal host cells_________ .

Accepted Answer

The answer of Animal viruses are more easily lysed compared...

Exam 9: Viruses and Virology

In the context of biogeochemical cycling, explain the role of bacteriophages and their impact on carbon cycling in the oceans.

Viral replication is

Viral size is generally measured in

Plant viruses can be difficult to work with because

Viral proteins are categorized as early and late. Early proteins are_________ , while late proteins include_________ .

A viroid

Explain the concept of a persistent infection in terms of a virus- infected cell.

Using T4 virions as a model, explain the concept of circular permutation.

The virus repressor protein

Which of the following are the hosts for most enveloped viruses?

Currently there is no formal system of viral taxonomy, although several systems are presently being developed.

When a virus enters a host cell in which it can replicate, the process is called a(n)_________ .

Temperate viruses can enter into either a lytic or lysogenic cycle.

The primer for retrovirus reverse transcription is a specific

Two chemical modifications of viral DNA that work to avoid host restriction mechanisms are_________ and _________.

Why is uncoating a step in the replication cycle of some animal viruses?

When packaged in the virion, the complete complex of nucleic acid and protein is known as the virus

Regarding the viral membrane in an enveloped virus, the lipids are derived from the_________, and the proteins are encoded by __________ .

Avirulent prions consist largely of_________ , whereas pathogenic prions have more regions.

Animal viruses are more easily lysed compared to prokaryotic cells, because animal host cells_________ .

Microorganisms and Microbiology

A Brief Journey to the Microbial World

Cell Structure and Function in Bacteria and Archaea

Nutrition, Culture, and Metabolism of Microorganisms

Microbial Growth

Molecular Biology of Bacteria

Archael and Eukaryotic Molecular Biology

Regulation of Gene Expression

Genetics of Bacteria and Arachaea

Genetic Engineering

Microbial Genomics

Phototrophy, Chemolithotrophy, and Major Biosyntheses

Catabolism of Organic Compounds

Commercial Products and Biotechnology

Microbial Evolution and Systematics

Bacteria: the Proteobacteria

Other Bacteria

Archaea

Eukaryotic Cell Biology and Eukaryotic Microorganisms

Viral Diversity

Methods in Microbial Ecology

Major Microbial Habitats and Diversity

Nutrient Cycles, Biodegradation, and Bioremediation

Microbial Symbioses

Microbial Growth Control

Microbial Interactions With Humans

Immunity and Host Defense

Immune Mechanisms

Molecular Immunology

Diagnostic Microbiology and Immunology

Epidemiology

Person-To-Person Microbial Diseases

Vectorborne and Soilborne Microbial Pathogens

Wastewater Treatment, Water Purification, and Waterborne Microbial Diseases

Food Preservation and Foodborne Microbial Diseases

Filters

Viral proteins are categorized as early and late. Early proteins are_ , while late proteins include_ .

Two chemical modifications of viral DNA that work to avoid host restriction mechanisms are_ and _.

Regarding the viral membrane in an enveloped virus, the lipids are derived from the_, and the proteins are encoded by __ .