(Section A: Virology) Lecture 01: Introduction to Virology Flashcards
What are the 3 levels of defense mechanisms?
- Intrinsic (skin, hair etc.)
- Innate Immunity
- Acquired Immunity
Are all viruses bad?
No, some viruses can form symbiogenic relationships with other organisms
List:
What is necessary for a virus to survive?
- Package genome inside particle
- Use particle to transfer genome from host to host
- Genome contains info to initiate/complete viral infectious cycle
- Genome establishes in host, ensures long-term survival
Dr. Dikeakos emphasizes:
What is key for viruses?
Genome
Viruses are…
Obligate, molecular parasites
* Means they are useless on their own
Do viruses grow?
No, they replicate
Do viruses always cause diseases?
No, it’s about a balance
* They occasionally cause sickness
* They occasionally stay dormant
How long have viruses existed? How did we find this out?
Over 250 million years
* Using molecular clock sequencing technology
What experiment is famous for giving the first definition of a virus?
Ivanovsky’s & Beijerinck’s Tobacco Mosaic Virus (TMV) Experiment
Describe:
The Tobacco Mosaic Virus Experiment
- Leaf was crushed
- Crushed leaf was filtered
What was the result from TBV Experiment?
- Crushed leaf did not infect others with disease
- Filtrate caused disease
Virus is filtrable
True or False:
Viruses can replicate on their own
False, they need a host in order to replicate
Describe:
The size of viruses
~1/1000 the size of E. coli
* Can be filtered through 0.2 micron filter
Are all viruses small?
Not exactly
* Mimiviruses can be seen under a light microscope
Define:
Virus
Very small, infectious, obligate intracellular parasite that needs cellular host