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25 Cards in this Set
- Front
- Back
What is a virus?
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an ultra-microscopic, intracellular, obligate parasite consisting of a core of infectious nucleic acid (either RNA or DNA) usually surrounded by a protein coat That can be single or multicomponent
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What is the function of the protein coat (capsid)?
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Protects nucleic acid
Serves to "fingerprint" a virus (antibody production) Specifically interacts with corresponding vector |
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Who is the Father of Virology
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Martinus Willem Beijerinck
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What is the morphology of viruses (types)?
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Spherical, Rigid rods, Flexuous rods, Bacilliform, Geminate
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Do the majority of plant viruses have DNA or RNA?
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RNA
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How do you find out the taxonomy of viruses?
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DNA/RNA sequences
Genome org Similar morph Effect on plant cells |
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How do you diagnose plant viruses?
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Pathogenicity-bioassays using indicator plants
Mode of Transmission-Vector transmission assays Electron microscopy Virus-specific structures Properties of protein coat-ELISA Properties of viral nucleic-PCR |
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What are the symptoms of a plant virus?
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stunting, mosaic, mottle, necrosis, distortion, stempitting, graft incompatibility, interveinal yellowing, vein clearing, ringspot, color break
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What are signs of plant viruses?
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particles using electron microscopy
inclusions |
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How are viruses transmitted?
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Insects, fungi, nematodes, seed, mechanical transmission, veg propagation
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What are the mechanisms of virus transmission?
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1. Non-persistent--"stylet-borne"; colonization not important for infection
2. Persistent--circulative; colonization important, circulateds in salivary glands, midgut or hemocoel 3. Persistent, circulative-propagative; replicates for entire life of insect |
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What are the components of a viroid?
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naked RNA
single stranded cavalent circles about 350 nucleotides in length no vector |
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How do you manage and control viruses?
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Certification programs
Quarantine and inspection Meristem culture for virus elimination Vector control Host plant resistance Cross protection |
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What is serology?
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a method using the specificity of the antigen-antibody reaction for the detection and identification of antigenic substances and the organisms that carry them
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What is ELISA?
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Enzyme-Linked ImmunoSorbent Assay; a serological test in which the sensitivity of the reaction is increased by attaching an enzyme that produces a colored product to one of the reactants
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What is a virion?
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complete virus particle
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What shape is a bacilliform particle?
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shaped like short rods with rounded ends
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What is an inclusion body?
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structure developed within a plant cell as a result of infection by a virus, often useful in identifying the virus
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What is an indicator plant?
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plant that reacts to a pathogen or an environmental factor with specific symptoms, used to detect or identify the pathogen or determine the effects of the environmental factor(inoculation of an indicator plant)
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What is a meristem culture?
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aseptic in vitro culture of a plant or plant part from a portion of the meristem; a method used to produce pathogen-free plants
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What is PCR?
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Polymerase Chain Reaction; a technique used to amplify the number of copies of a specific region of DNA in order to produce enough of the DNA for use in various applications such as identification and cloning
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What does contagium vivum fluidum mean and who came up with it?
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a contagious living fluid by Beijerinck
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What does single and multicomponent is a virus mean?
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Single is that the genes are located on a single piece of nucleic acid.
Multicomponent means that genes are located on more than one piece on nucleic acid. |
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What family and genus is Tomato spotted wilt virus in?
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Family Bunyaviridae
Genus Tospovirus |
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What is the vector of TSWV?
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thrips
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