Lecture 20 Flashcards
What are the classical definitions of life exhibited by viruses?
The ability to replicate
A nucleic acid genome
The ability to evolve
What is the complete and correct definition of a virus?
An obligate intracellular parasite which replicates from the assembly of individual components rather than an increase in the integrated sum of these components or division
What properties are common to all viruses?
A genome, A simple shape, the ability to reproduce, the ability to recognize and enter a specific subset of cells through interaction with one or more receptors on the surface of the cell
What are the differences between the evolution of viruses and the evolution of animals?
There is a higher mutation rate of viral genomes compared to animals ones due to the low fidelity of an RNA dep. RNA polymerase
Selection favours viruses best adapted to spread within a population during evolution
What is the role of quasi-species in defining viruses?
The term species defines similar viruses but ignores heterogeneity
Quasispecies is used to refer to the different “strains” of the virus
This can be determined by monoclonal antibody recognition RT-PCR
What are the methods for lab detection and analysis of viruses?
It can be done in whole animals
In organ cultures with one of the most successful methods using embryonated hens eggs
In lab grown tissue culture
What are the features of the reo family of viruses?
They are double stranded RNA viruses which are icosahedral and naked
What are the features of the Birna family of viruses?
Double stranded RNA viruses which are icosahedral, naked and have a segmented genome
What are the features of the Calici family of viruses?
Single stranded positive sense RNA viruses with a continuous genome and a naked icosahedral capsule
What are the features of the picorna family of viruses?
Single stranded positive sense RNA viruses with a continuous genome and a naked icosahedral capsule
What are the features of the flavi family of viruses
Single stranded positive sense RNA viruses with a continuous genome and enveloped icosahedral capsule
What are the features of the toga family of viruses?
Single stranded positive sense RNA viruses with a continuous genome and enveloped icosahedral capsule
What are the features of the retro family of viruses?
Positive sense RNA viruses with two copies of its genome and an enveloped icosahedral capsule
What are the features of the corona family of viruses?
A single stranded positive sense RNA virus with continuous genome and a enveloped helical capsule
What are the features of the filo family of viruses?
A single stranded negative sense RNA virus with a continuous genome and an enveloped helical capsule
What are the features of the rhabdo family of viruses?
A single stranded negative sense RNA virus with a continuous genome and an enveloped helical capsule
What are the features of the bunya family of viruses?
A single stranded negative sense RNA virus with a 3 segmented genome and an enveloped helical capsule
What are the features of the orthomyxo family of viruses?
A single stranded negative sense RNA virus with an 8 segmented genome and an enveloped helical capsule
What are the features of the paramyxo family of viruses?
A single stranded negative sense RNA virus with a continuous genome and an enveloped helical capsule
What are the features of the arena family of viruses?
A single stranded negative sense RNA virus with a 2 segmented genome and an enveloped helical capsule
What are the features of the Parvo family of viruses?
Non-linear DNA with a naked icosahedral capsid
What are the features of the papova family of viruses?
A double stranded, circular DNA virus, with a naked icosahedral capsid
What are the features of the adeno family of viruses?
A double stranded, linear DNA virus with a naked icosahedral capsid
What are the features of the hepadna family of viruses?
A double stranded, circle gapped DNA virus with an enveloped icosahedral capsid
What are the features of the herpes family of viruses?
A double stranded linear DNA virus with an enveloped icosahedral capsid
What are the features of the irido family of viruses?
A double stranded linear DNA virus with a icosahedral capsid which can be enveloped or naked
What are the features of the baculo family of viruses?
A double stranded circular DNA virus with an enveloped helical capsid
What are the features of the pox family of viruses?
A double stranded linear DNA virus with a coplex enveloped capsid
How can viruses be quantified without propagation in cells?
Hemagglutination and quantitative serological detection
What are the RNA family of viruses?
Reo, Birna, Calci, Picorna, Flavi, Toga, Retro, Corona, Filo, Rhabdo, Bunya, Orthomyxo, Paramyxo Arena
What are the DNA viral families?
Parvo, Papova, Adeno, Hepadna, Herpes, Irido, Baculo, Pox
What are the enveloped RNA viruses?
Flavi, Toga, Retro, Corona, Filo, Rhabdo, Bunya, Orthomyxo, Paramyxo, Arena
What are the naked RNA viral families?
Reo, Birna, Calci, Picorna
What are the enveloped DNA viral families?
Hepadna, Herpes, Irido, Baculo, Pox
What are the naked DNA viral families?
Parvo, Papova, Adeno
What RNA viral families use a helical capsule?
Corona, Filo, Rhabdo, Bunya, Orthomyxo, Paramyxo, Arena
What RNA viral families use an icosahedral capsule?
Reo, Birna, Calci, Picorna, Flavi, Toga, Retro
What are the double stranded RNA viral families?
Reo and Birna
What are the single stranded positive sense RNA viral families?
Calci, Picorna, Flavi, Toga, Retro, Corona
What are the single stranded negative sense RNA viral families?
Filo, Rhabdo, Bunya, Orthomyxo, Paramyxo Arena
