Viruses 1 Flashcards
What are viruses?
Viruses are sub cellular genetic material that are obligate parasites
What are the features of a virus?
Capsid (protein shell), nucleocapsid (capsid closest to genome), envelope (lipid membrane), matrix (connecting capsid to envelope)
What are the two types of capsid symmetry?
Icosahedral capsid or helical capsid
What are three viruses with icosahedral symmetry?
adenovirus, herpesvirus, papillomavirus
What are two viruses with helical symmetry?
mumps virus and influenza virus
Which virus does not pack as either icosahedral or helical?
poxvirus
What is a virus that is multi-shelled?
Rotavirus
What are the different types of viral genomes?
ssDNA, ssRNA, dsDNA, dsRNA, +ve sense (like mRNA), -ve sense (complementary to mRNA), linear, circular, segments
How are virus classified?
Based on their morphology, not the type of disease which they cause
What are the classification criteria?
nucleic acid, symmetry of capsid, naked or enveloped, genome architecture
Are there any helical DNA viruses?
No
Are there any helical RNA viruses without an envelope?
No
What are the groupings based on pathogenic criteria?
enteric, respiratory, hepatitis, arbovirus, sexually transmitted
What are the five methods of viral detection?
- visualisation by EM
- viral cultivation
- antigen detection
- serological response
- viral gene detection
