Chapter 13 Microbio
Consequences of lysogeny include ______.
lysogenic conversion immunity to superinfection
Infection of bacteria by phages always ends with the lysis of the host cell.
lytic
Outside of living cells, viruses are _______.
metabolically inert
Naked viruses do not have an outer lipid bilayer. These viruses are called - viruses.
non enveloped
Viruses that can cause cancer in humans are known as viruses.
oncogenic
HIV is described as a because it uses reverse transcriptase to make a DNA copy from its RNA genome.
retrovirus
Reassortment of gene segments that encode viral surface proteins recognized by the immune system can result in a loss of the immune system's ability to recognize and respond to the virus. This phenomenon is called antigenic
shift
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
Following the attachment of a T4 phage to an E. coli cell, the _________ of the phage contracts, and phage DNA is injected into the bacterial cell, leaving the phage coat outside.
tail
After a virus enters a cell, the nucleic acid separates from the protein coat, a process called
uncoating
The process by which the viral nucleic acid is released from the protective protein coat is ______
uncoating
The process by which the viral nucleic acid is released from the protective protein coat is ______.
uncoating
True or false: Lysogens are more susceptible to reinfection by the same type of phage.
False
Which form of transduction results from packaging errors during phage assembly?
Generalized
Which of the following describes a consequence of lysogeny that could 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
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
Which of the following statements about viruses are true?
The viral capsid is composed of protein. Viruses contain RNA or DNA but not both.
Which statements regarding viruses are true?
Viruses that infect bacteria are called bacteriophages
The accumulation of mutations in genes that encode viral surface proteins recognized by the immune system results in a type of antigenic variation called ______.
antigenic drift
Phage components are put together into mature virions during the step of the lytic cycle.
assembly
In order to infect an animal cell, viruses must ______.
attach to receptors on the host cytoplasmic membrane
List the steps of an animal virus infection cycle in the correct order. Start with the earliest at the top.
attachment penetration and uncoating synthesis of viral proteins and replication of the genome assembly release
Tumors are abnormal growths that result from a malfunction in the regulation of ______.
cell growth
In the lytic cycle of the T4 page, lysozyme degrades a portion of the bacterial ______.
cell wall
When an enveloped virus gains entry to an animal cell by fusion, the virus envelope fuses with the ______.
cytoplasmic membrane
Mutations in the influenza virus genome can result in minor changes in key viral surface proteins. This type of variation is called antigenic
drift
Which types of viruses are released by budding?
enveloped viruses
Viruses have three main shapes. The one shown in panel I is an example of a(n) virus, and the one in panel II is an example of a(n) virus
icosahedral helical
Viruses are best described as _______.
infectious agents
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
Bacteriophages that exit the host cell at the end of an infection by lysing it are called _______ phages.
virulent
True or false: Some lysogenic phages can increase the pathogenicity of their bacterial host.
True
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 term is used to describe the rupture or bursting of a bacterial cell following a phage infection.
release
A circular zone of clearing of phage-lysed bacteria in a lawn of bacteria is referred to as a(n) ______
plaque
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
Viruses that have an RNA genome and use reverse transcriptase to synthesize a DNA copy of that genome are called ______.
retroviruses
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
The viral genome is protected from the environment by a protein shell called the ______.
capsid
Enveloped viruses have an outer layer made up of _______.
lipid
Some pathogenic bacteria produce toxins that are encoded on prophage DNA, and these are examples of conversion.
lysogenic
A capsid is ______.
the protein coat that surrounds the viral genome
Which of the following describes the various viral parts coming together to produce virions?
Assembly
transduction is the result of packaging errors during the assembly stage of phage replication.
Generalized
Which facts best support the position that viruses are not living organisms?
Viruses cannot reproduce on their own. Viruses are inert outside of a host.
When two different strains of a segmented virus enter the same cell, reassortment of the gene segments can occur, resulting in ______.
antigenic shift
During the or maturation step in viral multiplication, capsids and genetic material are packaged into virions.
assembly
Regarding animal viruses, which of the following statements are true?
Some viruses require more than one host receptor for attachment. Viruses use their spikes to attach to host cell receptors. Blocking a host receptor with a drug would prevent a virus from infecting that cell.
Viruses that infect bacteria are called
bacteriophages
The stage of viral multiplication at which budding occurs is ______
release
