Chapter 6 - Connect Exercise
Which of the following statements about viruses are true?
- Viruses contain RNA or DNA but not both. - The viral capsid is composed of protein.
productive infection latent state
- new viral particles are produced - viraL genome remain silent within the cell
Bacteriophages that exit the host cell at the end of an infection by lysing it are called _______ phages.
virulent
Which are the two major categories of viral infections?
Persistent Acute
The major categories of animal viral infections are ____ infections, characterized by the sudden onset of symptoms of a relatively short duration, and infections that can continue with or without symptoms for years.
acute persistent
During the ___ or maturation step in viral multiplication, capsids and genetic material are packaged into virions.
assembly
Multiple Choice Question When an enveloped virus gains entry to an animal cell by fusion, the virus envelope fuses with the ______.
cytoplasmic membrane
The process by which a virus is taken up by a host cell as a result of the host cell's cytoplasmic membrane surrounding the virion to form a vesicle is called ______.
endocytosis
Which types of viruses are released by budding?
enveloped viruses
True or false: There is no need to classify viruses because they are not living organisms.
false
Multiple Choice QuestionYour Answer incorrect Which of the following phage types cause productive infections that do not kill the host cell?
filamentous
Which of the following phage types cause productive infections that do not kill the host cell?
filamentous
transduction is the result of packaging errors during the assembly stage of phage replication.
generalized
In the case of animal viruses, the molecules that viral spikes attach to on the host cell in order to gain entry are typically ______.
glycoproteins
The study of bacteriophages has advanced much faster than investigations on animal viruses in part because ______.
it is easier to grow bacterial cells than animal cells
Animal viruses can be studied by infecting
live animals cell or tissue culture fertilized chicken eggs
Infection of bacteria by ____ phages always ends with the lysis of the host cell.
lytic
Viruses that specifically target and kill cancer cells are called
oncolytic
In which type of infection does the virus remain in the host for years, sometimes without symptoms?
persistent
In a(n) ______, viral titer can be determined by counting clear zones in a monolayer of cells.
plaque assay
An infectious agent that consists of protein and no nucleic acid is called a(n)
prion
Infectious agents that have a simpler structure than viruses include
prions and viroids
Which form of transduction results from excision errors during the transition from a lysogenic to lytic cycle?
specialized
transduction is the result of excision errors made as temperate phages transition from a lysogenic to a lytic cycle.
specialized
Attachment of animal viruses to the host cell typically occurs by means of ______
spikes
A ______ phage can either cause a lytic infection or can incorporate its DNA into the host genome as a prophage.
temperate
Bacteriophages that can enter into a lytic cycle or a lysogenic cycle are called ____ phages.
temperate
phages cause productive infections that do not kill the host cell.
temperate
Human cells are larger than viruses by which size factor?
thousand
Bacteriophages play a fundamental role in a type of horizontal gene transfer called
transduction
An abnormal growth of tissue resulting from a malfunction in the normally highly regulated process of cell growth is a
tumor
A _______ is a single virus particle.
virion
A complete viral particle, which typically consists of nucleic acid surrounded by a protein coat, is called a(n)
virion
is an infectious agent that lacks a capsid and consists only of RNA.
viroid
Which of the following are non-cellular infectious agents?
Viroids Viruses Prions
A prion is best described as ______.
a proteinaceous infectious agent
Infectious agents that have a simpler structure than viruses include ______
both viroids and prions
Oncoviruses are viruses that can ______.
cause cancer in humans
If viruses are present in high enough concentrations in a sample, they can be quantified directly using a(n)
electron microscope
Which form of transduction results from packaging errors during phage assembly?
generalized
Bacteriophages that can enter into a lytic cycle or a lysogenic cycle are called virulent phages
na
The smallest virus is approximately 10 ______ in diameter.
nanometers
The stage of viral multiplication at which budding occurs is ______.
release
What term is used to describe the transfer of genetic information from one bacterium to another bacterium by a bacteriophage?
transduction
Which of the following are non-cellular infectious agents composed of only a single-stranded RNA molecule?
viroids
Why are bacteriophages easier to study than animal viruses?
It is easier to grow the bacteriophage host cells in the lab.
Which of the following about classifying viruses is FALSE?
It is not as important as classifying organisms since they are not living entities.
Which of the following describe a type of relationship that bacteriophages can have with their host?
Latent infection where host cell genotype is changed Productive lytic infection
Which of the following processes are required for production of virus particles in a host cell?
Transcription of viral genes Translation of viral genes Replication of viral genome
All of the following are required for synthesis of new virus particles in a host cell EXCEPT ______.
homoelogous recombination
All of the following are required for synthesis of new virus particles in a host cell EXCEPT ______.
homologous recombination
Symptoms of acute viral diseases result from ______.
host tissue damage host immune respons
Viruses are best described as _______
infectious agents
Viruses are best described as _______.
infectious agents
