Chapter 31 - Intro to Virology and Phage Flashcards
describe viruses
- simple organization
-DNA or RNA genome - unable to reproduce outside of living cells
- obligate intracellular parasites
describe cellular organisms
- complex organization
- DNA genome and RNAs
- carry out cell division
- some are obligate intracellular parasites
what are the 3 theories of viral origin
- reductive origin: viruses evolved by degenerative evolution from intracellular parasitic cells
- theory of intracellular origin: viruses evolved from functional parts of cells that acquired an ability to reproduce themselves uncontrolled by the cell
- theory of independent origin holds that viroid nucleic acids could have evolved outside of cells during the RNA world and acquired the ability to infect cells
how big are pandoraviruses
1000nm
what is the biggest virus
pandora virus
multicomponent viruses genomes are segmented and the segments are distributed into _____
separate viral particles
cultivation of viruses requires inoculation of living host cells. what are examples of the host cells
- suitable animals
- embryonated eggs
- tissue cultures
- cytopathic effects (CPEs)
what can tissue (cell) cultures be
- monolayers of animal cells
- plaques: localized area of cellular destruction and lysis
what are cytopathic effects (CPEs)
microscopic or macroscopic degenerative changes or abnormalities in host cells and tissues
what makes up a nucleocapsid/naked capsid virus
- DNA or RNA + structural proteins +/- enzymes and nucleic acid binding proteins
what makes up an enveloped virus
nucleocapsid + glycoproteins and membrane
what makes up icosahedral symmetry
- nucleocapsid made of
- capsid
- capsomers
- nucleic acids
what virus has icosahedral capsid symmetry
herpes
what is an example of a virus with helical symmetry
ebola virus filaments (SEM)
what do enveloped viruses have vs nonenveloped
glycoprotein spikes and lipid bilayer
what is an example of an asymmetrical virus
vaccinia poxvirus