Viral Replication/Transcription/Translation Examples

Question 1

In which stage is the viral DNA introduced into the cell? (Virulent Bacteriophages)

Answer 1

Penetration

Question 2

In which stage does formation of mature viruses occur? (Virulent Bacteriophages)

Answer 2

Assembly

Question 3

The host DNA is usually degraded during which stage? (Virulent Bacteriophages)

Answer 3

Biosynthesis

Question 4

What would be the fate of a lytic bacteriophage if the host cell died prior to the assembly stage?
(Virulent Bacteriophages)

Answer 4

The virus would not be able to infect new hosts.

Question 5

Lysogenic viral DNA integrating into the host genome is referred to as
(Temperate Bacteriophages)

Answer 5

a prophage.

Question 6

Which of the following events might trigger induction of a temperate bacteriophage?
(Temperate Bacteriophages)

Answer 6

Exposure to UV light

Question 7

How is the lytic cycle different from the lysogenic cycle with respect to the infected host cell?
(Temperate Bacteriophages)

Answer 7

The host cell dies during the lytic stage.

Question 8

What is the fate of the prophage during the lysogenic stage?
(Temperate Bacteriophages)

Answer 8

It is copied every time the host DNA replicates.

Question 9

Are virophages a type of virus or something different?

Answer 9

It must have a capsid and a nucleic acid, which can be double-stranded or single-stranded, circular or linear, and DNA or RNA. Virophages are therefore a type of virus.

Question 10

Virophages only

Answer 10

• smaller than bacteria and archaea
• lack genes for proteins needed to self replicate

Question 11

Non-virophage viruses only

Answer 11

genetic information can be in the form of DNA and RNA

Question 12

Both virophages and other viruses

Answer 12

-can’t replicate on their own
- don’t belong to the 3 domains
- have a protein capsid surrounding their nucleic acid

Question 13

Neither virophages nor other viruses

Answer 13

• generate energy through mitochondria
• use ribosomes to make proteins

Question 14

what is another way that cells have evolved to avoid viral infection?

Answer 14

An attachment receptor on the host cell surface that is recognized by the virus is mutated.

Question 15

Viruses have many types of life cycles and can go through phases during which they are actively replicating and destructive to the host cell or dormant within the host cell. These life cycles differ in different types of viruses, so the cycle of megaviruses differs from those of bacteria and animals. During which part of the bacteriophage life cycle will the viral genome be replicated in synchrony with the host cell?

Answer 15

lysogenic

Question 16

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

Answer 16

nucleocapsid

Question 17

Reverse transcriptase is a(n)

Answer 17

RNA-dependent DNA polymerase.

Question 18

The latent phase in the viral growth curve and the lag phase of the bacterial growth curve are equivalent and represent the time it takes for the virus or bacterium to adapt to the culture conditions and begin growing.

Answer 18

False

Question 19

Viral proteins are categorized as early, middle, and late. Early proteins typically are necessary for

Answer 19

production of viral mRNA and copying the viral genome.

Question 20

T4 genes are transcribed by host RNA polymerase, yet this transcription is carefully controlled so that groups of T4 genes are transcribed in a specific order after infection. How is this accomplished?

Answer 20

Early and middle T4 genes encode for RNA polymerase-modifying proteins so that only phage promoters are recognized.