CH 13 - Microbiology
Infectious agents that have a simpler structure than viruses include _______
both viroids and prions
A person that had chickenpox will be latently infected with VZV (varicella zoster virus). This means that they ________
can have shingles later on if the virus reactivates
Beign
does not spread to nearby tissue
Bacteriophages play a role in two types of transduction: ________ and _________
generalized specialized
Any gene of the donor cell can be transferred to the recipient cell. This statement describes what type(s) of transduction?
generalized transduction only
A _________ tumor is one that can metastasize or spread to nearby tissue
malignant
In terms of susceptibility to soaps, detergents, and disinfectants, enveloped viruses are _________ non-enveloped viruses
more susceptible than
The smallest virus is approximately 10 ______ in diameter
nanometers
Productive infection
new viral particles are produced
Which of the following are non-cellular infectious agents?
viruses viroids prions
Lysogeny is best described as _______
integration of the viral genome into the host chromosome
Enveloped viruses have an outer layer made up of _______
lipid
At minimum, all viruses are composed of
nucleic acids and proteins
Viroids are pathogens of ______
plants only
Malignant
spreads to nearby tissue
Proto-oncogene
stimulates cell growth
A _____ is a single virus particle
virion
Which of the following statements about prions are true?
Infectious prion proteins are insoluble and aggregate in brain tissue Infectious prion proteins have a different shape from normal prion proteins Infectious prion proteins may convert normal prion proteins into an abnormal form
The viral genome is protected from the environment by a protein shell called the ______
capsid
A viral capsid is made up of subunits called ______
capsomeres
Tumors are abnormal growths that results from a malfunction in the regulation of _______
cell growth
Which type of viral infection is characterized by the continuous, low level production of new virus particles by animal host cells?
chronic
Which of the following are classified as persistent infections?
chronic infections latent infections
Typical route of infection for mad cow disease appears to be via _______
consumption of contaminated food
Viral genomes can be _____
either single stranded or double stranded
Viral genomes can be _______
either single stranded or double stranded
The virus that causes COVID-19 is ______ and phages are typically ______
enveloped non-enveloped
True or False: All virus infections can be clearly characterized as either acute or persistent
false
Which form of transduction results from packaging errors during phage assembly?
generalized
_______ transduction is the result of packaging errors during the assembly stage of phage replication
generalized
During specialized transduction, DNA from another bacterial cell may be integrated into the recipient cell chromosome by ________ recombination
homologous
In specialized transduction, bacterial DNA may be integrated into the host genome by ______
homologous recomination
Tumor suppressor gene
inhibits cell growth
A viral infection in which the viral genome is integrated into an animal host cell chromosome, yet can reactivate to cause a productive infection, is categorized as a(n) __________ infection
latent
Which of the following infections are analogous to lysogenic infections by bacteriophages in that they involve a viral genome that is silent in the host cell?
latent
Which of the following describes a consequence of lysogeny that result in human disease?
lysogenic conversion
_______ is a change in the phenotype of a lysogen as a consequence of the specific prophage it carries
lysogenic conversion
Infection of bacteria by _____ phages always end with the lysis of the host cell
lytic
Naked viruses do not have an outer lipid bilayer. These viruses are called _________ viruses
non enveloped
In latent infections, the virions are ________
only produced during reactivation
In which type of infection does the virus remain in the host for years, sometimes without symptoms?
persistent
Which are the two major categories of viral infections?
persistent acute
_____ infections remain for years, or even the lifetime of the host, sometimes without any symptoms
persistent or chronic
An infectious agent that consists of protein and no nucleic acid is called a(n) ______
prion
Mad cow disease and chronic wasting disease are caused by infectious agents called _______
prions
Mad cow disease and chronic wasting disease are caused by infectious agents called ________
prions
Transmissible spongiform encephalopathies are caused by ______
prions
Transmissible spongiform encephalopathies are caused by _______
prions
In a lysogenic infection, the phage DNA that is incorporated into the bacterial host genome is called a ________
prophage
Control of cell growth and division are controlled by two sets of genes: those that stimulate growth are called __________ and those that inhibit growth are called _____________ genes
proto-oncogenes tumor suppressor
In _________ transduction, only bacterial genes adjacent to the prophage can be transferred
specialized
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
Many animal viruses have proteins called ______ that attach to receptors on host cells
spikes
The viral proteins that stick out from either the lipid bilayer of enveloped viruses or the capsid of non-enveloped viruses, and attach to host cells are ________
spikes
A _____ phage can either cause a lytic infection or can incorporate its DNA into the host genome as a prophage
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
True or False: It appears that mad cow disease can be transmitted to humans through consumption of infected beef
true
Viroids ______
cause serious plant disease
Bacteriophages that can enter into a lytic cycle or a lysogenic cycle are called ________ phages
temperate
The capsid of a virus is composed of precisely arranged identical protein subunits called ______
capsomeres
Which suffix represents a viral genus?
-virus
True or False: Normal prion proteins can have the same amino acid sequence as the abnormal form of the protein
True
A generalized infection cycle of an animal viruses can be divided into five steps: 1. _________; 2 ___________ entry, 3. ____________, 4 __________ and 5 _______
attachment genome synthesis assembly release
Following generalized transduction, DNA from the donor cell may be integrated into the recipient cell chromosome by _____ recombination
homologus
The two categories of persistent infections are _________ and ___________
latent chronic
The typical symptoms of cold sores can be caused by _______
latent HSV-1 that has reactivated an initial infection with HSV-1
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
A(n) _______ is an animal virus genome that has integrated into the genome of the host cell
provirus
List the steps of an animal virus infection cycle in the correct order
attachment penetration and uncoating synthesis of viral proteins and replication of the genome assembly release
An animal virus genome residing silently in a host cell genome is called a(n) _______A
provirus
HIV infection _______
has features of both acute and persistent infections
Bacteriophages that exit the host cell at the end of an infection by lysing it are called ______ phages
virulent
Which of the following are non-cellular infectious agents composed of only a single-stranded RNA molecule?
viroids
________ are the causative agents of transmissible spongiform encephalopathies
Prions
Specialized transduction ________
produces defective phage particles results from errors in excision of the prophage transfers phage DNA and adjacent host genes
Infectious agents that consist entirely of RNA and that infect plants only are called ________
viroids
During the proposed mechanism of prion replication, the infectious prion protein _______ interacts with the normal protein _________ causing it to misfold
PrP^SC, PrP^C
Symptoms of acute viral diseases result from ________
host immune response host tissue damage
Which of the following are caused by viroids?
citrus exocortis disease potato spindle tuber disease cucumber pale fruit disease
Latent state
viral genome remains silent within the cell
A ________ is a single virus particle
virion
Specialized transduction __________
produces defective phage particles results from errors in excision of the prophage transfer phage DNA and adjacent host genes
A ______ phage can either cause a lytic infection or can incorporate its DNA into the host genome as a prophage
temperate
An abnormal growth of tissue resulting from a malfunction in the normally highly regulated process of cell growth is a ________
tumor
A complete viral particle, which typically consists of nucleic acid surrounded by a protein coat, is called a(n) ______
virion
Infection of bacteria by _____ phages always ends with the lysis of the host cell
lytic
The nucleocapsid is composed of ____
DNA or RNA, and protein
True or False: Lysogens are more susceptible to reinfection by the same type of phage
False
Which of the following statements describes the mechanism by which prions replicate?
PrP^SC interacts with PrP^C, converting it to PrP^SC
Which of the following are diseases caused by prions?
Scapie Bovine spongiform encephalopathy Creutzfeldt-Jakob disease
Which of the following statements about virus nucleic acid is true?
Viruses contain either DNA or RNA
A prion is best described as ______
a proteinaceous infectious agent
Generalized transducing particles contain which of the following?
bacterial genes
The suffix ______ indicates a viral family
-viridae
Phage heads that contain only bacterial DNA are called generalized __________ particles
transducing
Bacteriophages play a fundamental role in a type of horizontal gene transfer called _________
transduction
Infectious agents that have a simpler structure than viruses include ________
both viroids and prions
Consequences of lysogeny include _______
immunity to superinfection lysogenic conversion
Infectious agents that consist entirely of RNA and that infect plants only are called _______
viroids
The capsid of a virus is composed of precisely arranged identical protein subunits called ________
capsomers or capsomeres
True or False: Normal prion proteins can have the same amino acid sequence as the abnormal form of the protein
true
Which type of infection can be characterized by the sudden onset of symptoms of a relatively short duration?
acute
A capsid is ____
the protein coat that surrounds the viral genome
What term is used to describe the transfer of genetic information from one bacterium to another bacterium by a bacteriophage?
transduction
In acute viral infections, although the infected host cells may die, the host may survive because _________
the host's immune system may gradually eliminate the virus
Infections that have a sudden onset of symptoms of relatively short duration are described as _______ infections
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
The hepatitis B virus sometimes causes an infection that results in a continuous and low-level production of virus particles. This type of infection pattern is specifically described as a(n) _______ viral infection
chronic
A(n) _______ is an infectious agent that lacks a capsid and consists only of RNA
viroid
