Oncoviruses bacteriophage a virus most contain double

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oncoviruses Bacteriophage- a virus; most contain double stranded DNA, although single stranded DNA and RNA types exist as well o Every bacterial species is parasitized by various bacteriophages
o Ex. E.Coli; T-even phages o Host cell becomes so packed with viruses that it lyses (splits open) thereby releasing the mature virions o New type of virus virophages parasitize other viruses that are infection the same host cell they infect using genes from other (usually larger ) viruses for their own replication and production Lysogeny: The Silent Virus Infection Temperate Phages - can participate in a lytic phase, also have the ability to undergo adsorption and penetration into the bacterial host and not undergo replication or release immediately o Can increase the pathogenicity of a bacterium Instead, viral DNA enters an inactive prophage state, during which it is inserted into the bacterial chromosome v - condition in which the host chromosome carries bacteriophage DNA; bacterial cells carrying temperate phages do not lyse and they appear entirely normal o Lysogeny is a less deadly form of parasitism than the full lytic cycle and is thought to be an advancement that allows the virus to spread without killing the host The Danger of Lysogeny in Human Disease Many bacteria that infect humans are lysogenized by phages; Occasionally phage genes in bacterial chromosome cause the production of toxins or enzymes that cause pathology in the human Lysogenic conversion- when bacterium acquires a new trait from its temperate phage Primary Purposes of Viral Cultivation Isolate and identify viruses in clinical specimens Prepare viruses for vaccines Do detailed research on viral structure, multiplication cycles, genetics, and effects on host cells Which cellular organisms can viruses infect? Bacteria Plants Fungi Protozoa Animals Viruses (active/inactive) Bacteria (alive/dead)
Host range defines the limitation of the type of cell that a virus can invade Bacteriophage- the types of viruses tat infect bacteria Prophage- phage DNA that is latently incorporated into the bacterial host genome Lysogeny is best described as integration of the viral genome into the host Temperate phages enter the prophage state, while lytic phages burst the host cell Temperate phage- can incorporate itself into the host genome as a lysogenic prophage When bacteriophages infect pathogenic bacteria resulting in a new pathogenic trait, it's called lysogenic conversion A provirus is an animal virus which has integrated its DNA into the DNA of its host cell

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