Chapter 8 Viruses And Virology

Question 1

Capsid

Answer 1

Protein shell that surrounds the genome of a virus particle

Question 2

Capsomere

Answer 2

The subunit of a capsid

Question 3

Concatemer

Answer 3

Two or more linear nucleic acid molecules joined covalently in tandem

Question 4

Early protein

Answer 4

A protein synthesized soon after virus infection and before replication of the virus genome

Question 5

Enveloped

Answer 5

In reference to a virus, having a lipoprotein membrane surrounding the virion

Question 6

Host cell

Answer 6

A cell inside which a virus replicates

Question 7

Late protein

Answer 7

A protein, typically a structural protein, synthesized late in virus infection

Question 8

Lysogen

Answer 8

A bacterium containing a prophase

Question 9

Lysogeny

Answer 9

A state in which the viral genome is replicated in step with the genome of the host

Question 10

Lytic pathway

Answer 10

The type of virus infection that leads to virus replication and destruction of the host cell

Question 11

Bacteriophage

Answer 11

A virus that infects bacterial cells

Question 12

Middle protein

Answer 12

Protein with either a structural or catalytic function synthesized after the early proteins in a virus infection

Question 13

Nucleocapsid

Answer 13

The complex of nucleic acid and proteins of a virus

Question 14

Overlapping genes

Answer 14

Two or more genes in which part or all of one gene is embedded in the other

Question 15

Plaque

Answer 15

A zone of lysis or growth inhibition caused by virus infection of a lawn of sensitive host cells

Question 16

Prophage

Answer 16

The lysogenic form of a bacteriophage

Question 17

Provirus

Answer 17

The genome of a temperate or latent animal virus when it is replicating in step with the host chromosome

Question 18

Replicative form

Answer 18

A double-stranded DNA molecule that is an intermediate in the replication of viruses with single-stranded DNA genomes

Question 19

Retrovirus

Answer 19

A virus whose RNA genome is replicated via a DNA intermediate

Question 20

Reverse transcriptase

Answer 20

The retroviral enzyme that can produce DNA from an RNA template

Question 21

RNA replicase

Answer 21

An enzyme that can produce RNA from an RNA template

Question 22

Rolling circle replication

Answer 22

A DNA replication mechanism in which one strand is nicked and unrolled for use as a template to synthesize a complementary strand

Question 23

Temperate virus

Answer 23

A virus whose genome can replicate along with that of its host without causing cell death, in a state called lysogeny (bacterial viruses) or latency (animal viruses)

Question 24

Titer

Answer 24

The number of infections virions in a viral suspension

Question 25

Virion

Answer 25

The infectious virus particle, the viral genome surrounded by a protein coat and sometimes other layers

Question 26

Virulent virus

Answer 26

A virus that lyses or kills the host cell after infection

Question 27

Virus

Answer 27

A genetic element containing either RNA or DNA surrounded by a protein capsid and that replicates only inside host cells

Question 28

How does a virus differ from a cell?

Answer 28

Shape (typically smaller), genome length and the amount of genes encoded based on RNA or DNA usage, cannot replicate on its own and needs a virion to survive outside host cell

Question 29

Why does a virus need a host cell?

Answer 29

Because it relies on the host cell’s energy for energy, metabolic intermediates, protein synthesis