Question 1

Describe the hypothesis of viruses occurring before living cells and how DNA might have evolved. What is the current hypothesis about the evolutionary relationships between RNA, DNA, viruses, and cellular life?

Accepted Answer

The answer of Describe the hypothesis of viruses occurring before...

Question 2

A drug designed to inhibit reverse transcriptase activity would target

Accepted Answer

A)  coronaviruses and rhabdoviruses. 
B)  retroviruses. 
C)  hepadnaviruses and retroviruses. 
D)  viruses with RNA genomes.

Question 3

A bacteriophage that lacks its proteinaceous capsid structure is also called a viroid.

Accepted Answer

A) True 
 B)False

Question 4

Unusually shaped viruses, such as lemon-shaped and spindle-shaped, have recently been discovered in

Accepted Answer

A)  Archaea. 
B)  Bacteria. 
C)  Archaea and Bacteria. 
D)  Eukarya.

Question 5

The family of reoviruses contain dsRNA genomes use a ________ replication process.

Accepted Answer

A)  conservative 
B)  semiconservative 
C)  retroviral 
D)  rolling circle

Question 6

The ________ has been especially useful for genetic engineering because it is capable of triggering a substantial immune response without causing major adverse health effects.

Accepted Answer

A)  adenovirus 
B)  polymyxavirus 
C)  vaccina virus 
D)  herpesvirus

Question 7

Among the largest RNA genome viruses are ________ which contain a ________ genome.

Accepted Answer

A)  coronaviruses / dsRNA 
B)  coronaviruses / positive ssRNA 
C)  polioviruses / dsRNA 
D)  polioviruses / positive ssRNA

Question 8

Genomics analysis of recently isolated viruses indicate that some viruses contain larger genomes than some bacterial genomes.

Accepted Answer

A) True 
 B)False

Question 9

Bacteriophages that have single-stranded genomes are specialized to minimize energy requirements because just one strand is necessary for replication.

Accepted Answer

A) True 
 B)False

Question 10

Due to their indispensible role for copying its genome, an intracellular host protease that attacks the adenoviral protein ends would likely result in halting its replication.

Accepted Answer

A) True 
 B)False

Question 11

The hepadnavirus DNA polymerase acts as which of the following?

Accepted Answer

A)  DNA polymerase 
B)  reverse transcriptase 
C)  protein primer for synthesis of a strand of DNA 
D)  DNA polymerase, reverse transcriptase, and protein primer for DNA synthesis

Question 12

Despite viruses require a living hostʹs metabolism to replicate, it remains unclear whether viruses existed before living cells.

Accepted Answer

A) True 
 B)False

Question 13

One hypothesis on the origin of DNA points to RNA viruses evolving a modified nucleotide that is insensitive to ribonucleases.

Accepted Answer

A) True 
 B)False

Question 14

Many viruses that infect humans may illicit a strong immune response causing additional harmful effects, so the discovery of a virus that can induce an immune response without causing harm made it attractive for vaccine development.

Accepted Answer

A) True 
 B)False

Question 15

Why are phylogenetic studies of viruses more challenging than Bacteria? Explain how genes are selected in viruses for phylogeny and the constraints those create.

Accepted Answer

The answer of Why are phylogenetic studies of viruses more...

Question 16

Nonfilamentous bacteriophages often can escape its host without lysing, whereas filamentous phages normally induce cell lysis once replicated inside their host.

Accepted Answer

A) True 
 B)False

Question 17

The phage Mu

Accepted Answer

A)  has a circular genome. 
B)  repairs mutations in the host genome. 
C)  replicates by transposition. 
D)  has a circular genome, repairs host genome mutations, and can replicate by transposition.

Question 18

What will happen if the Mu repressor is NOT synthesized?

Accepted Answer

A)  Genome replication will not be able to occur. 
B)  It will lyse its host. 
C)  Mu will improperly synthesize its capsid. 
D)  Transposition will not be possible.

Question 19

Describe how bacteriophages influence the oceans' bacterial populations and nutrient cycling.

Accepted Answer

The answer of Describe how bacteriophages influence the oceans' bacterial...

Question 20

Due to the genetic diversity of viruses and their lack of ribosomal RNA, nucleotide-based phylogeny studies are not applicable to virology.

Accepted Answer

A) True 
 B)False

Exam 10: Viral Genomics, Diversity, and Ecology

Describe the hypothesis of viruses occurring before living cells and how DNA might have evolved. What is the current hypothesis about the evolutionary relationships between RNA, DNA, viruses, and cellular life?

A drug designed to inhibit reverse transcriptase activity would target

A bacteriophage that lacks its proteinaceous capsid structure is also called a viroid.

Unusually shaped viruses, such as lemon-shaped and spindle-shaped, have recently been discovered in

The family of reoviruses contain dsRNA genomes use a ________ replication process.

The ________ has been especially useful for genetic engineering because it is capable of triggering a substantial immune response without causing major adverse health effects.

Among the largest RNA genome viruses are which contain a genome.

Genomics analysis of recently isolated viruses indicate that some viruses contain larger genomes than some bacterial genomes.

Bacteriophages that have single-stranded genomes are specialized to minimize energy requirements because just one strand is necessary for replication.

Due to their indispensible role for copying its genome, an intracellular host protease that attacks the adenoviral protein ends would likely result in halting its replication.

The hepadnavirus DNA polymerase acts as which of the following?

Despite viruses require a living hostʹs metabolism to replicate, it remains unclear whether viruses existed before living cells.

One hypothesis on the origin of DNA points to RNA viruses evolving a modified nucleotide that is insensitive to ribonucleases.

Many viruses that infect humans may illicit a strong immune response causing additional harmful effects, so the discovery of a virus that can induce an immune response without causing harm made it attractive for vaccine development.

Why are phylogenetic studies of viruses more challenging than Bacteria? Explain how genes are selected in viruses for phylogeny and the constraints those create.

Nonfilamentous bacteriophages often can escape its host without lysing, whereas filamentous phages normally induce cell lysis once replicated inside their host.

The phage Mu

What will happen if the Mu repressor is NOT synthesized?

Describe how bacteriophages influence the oceans' bacterial populations and nutrient cycling.

Due to the genetic diversity of viruses and their lack of ribosomal RNA, nucleotide-based phylogeny studies are not applicable to virology.