Chapter 6 microbiology
Rank the following viruses from smallest to largest
1. Yellow Fever 2. Phage T2 3. Influenza 4. Herpes 5. Poxvirus 6. Megavirus
The capsid of a viral particle is composed of identical proteins called ____
Capsomers
Reovirus Cytopathic effect
Cell enlargement
Rabies virus cytopathic effect
No change in cell shape
___ viruses can infect host cells and later lead to cancer
oncogenic
True or false The hepadnavirus family is so named because viruses within the family infect the liver and possess DNA as their genetic material.
True
True or false The viral host relationship is extremely important for pathogenicity, mode of transmission, the immune response, and the human measures used to control viral infections
True
True or false Viral nuclei acid enters the host cell and uses the host cells replication and synthesis machinery in order to produce new nucleic acid molecules, proteins for the capsid, spikes, and viral enzymes
True
penetration stage of viral replication
Virus is engulfed in a vesicle or endosome and transported internally
Which of the following characteristics are associated with transformed cells?
altered chromosomes changes in cell surface molecules integration of viral DNA into host chromosome
Please select all of the following that represent viral characteristics
are obligate intracellular parasites have a 20 to 450 nanometer diameter are composed of a capsid surrounding a nucleic acid core
Cytopathic changes in virally infected animal cells include
inclusions in the cytoplasm clumping of cells cell lysis cytoplasmic inclusions formation of multinucleate syncytia
True or false The light microscope was critical in the discovery of the viruses
False
Viruses first appeared on Earth sometime after the rise of eukaryotic organisms.
False
Measles virus Cytopathic effect
Formation of syncytia cell fusion?
What data or achievement was instrumental to the initial characterization of viruses?
the discovery that infectious fluid remained infectious even when passed through a filter designed to trap bacteria
Together, the capsid and the nucleic acid are referred to as the _____.
nucleocapsid
All viruses
possess a capsid composed of protein are reliant on a host cell for their own reproduction
The special affinity that a virus has for a particular type of tissue is called a __________.
tropisms
Fully formed viral particles capable of establishing infection in a new host are called ____
virions
adenovirus cytopathic effect
Clumping of cells
virus-induced damage to the host cell, called ____ effecta, can include changes in the cell size and shape
Cytopathic
Select all of the statements that are true regarding penetration of animal viruses
Enveloped viruses can penetrate by fusion, Enveloped viruses can penetrate by endocytosis, Nonenveloped viruses can penetrate by endocytosis, Once inside the host, viruses become uncoated.
True or false The envelope is entirely formed from the viral material
False
True or false Viral replication follows essentially the same steps as prokaryotic cells
False
True or false Virus are classified into species based on whether they can reproduce to produce fertile offspring, much like plants and animals
False
Which of the following are the most useful using modern system to classify a newly discovered virus?
Genome RNA, envelope contains particular spike proteins, Capsid is isosahedral
Regarding replication of an enveloped animal virus, match the stage of replication with its definition.
Release, synthesis, adsorption, penetration, assembly, uncoating
helical capsid
Rod-shaped capsomeres that bind together too resemble a bracelet
Influenza Cytopathic effect
Rounding up of cells
Feline leukemia virus may be lethal to cats but does not infect humans. This is a reflection of
The host range of feline leukemia virus
Which of the following are true about viral envelopes
They are composed of host membrane, They can contain host-encoded proteins, They can contain virus-encoded proteins, They are important for binding to host cells.
icosahedral capsid
Three-dimensional, 20-sided figure with 12 evenly spaced corners
Please select the characateristics that are used to identify and name viruses
Type of capsid, Type of envelope, Nucleic acid strand number, Area of rhe host cell in which the virus multiplies
Synthesis Stage of viral replication
Under control of viral genes, the host cell synthesis all the components needed to assemble new viral particles
Uncoating stage of viral replication
Vesicle membrane and viral envelope fuse, releasing capsid into the host cytoplasm
poliovirus cytopathic effect
cell lysis; no inclusions
What is the true concerning the viral envelope ?
It contains viral proteins, It was once a part of the host cell.
Which of the following terms is associated with the release of nonenveloped or complex viruses from the host cell?
Lysis
release stage of viral replication
Viruses bud of from the host cell membrane
Assembly Stage of viral replication
Viral nucleic acid encased in capsid, viral proteins inserted in host cell membrane
The "Adsorption" stage of the viral replication cycle involves
Virus attached to its host cell by binding cell surface receptors