VIRUSES Flashcards
What are the largest viruses the same size as?
The smallest bacteria
The largest viruses have the same amount of DNA as ___________
parasitic eukaryotes
Viruses are vehicles of ______ gene transfer
horizontal
Human chromosomes are full of __________ genes
non-functional viral
What is the viral mutation rate?
1 in 10000 nucleotides
What helps viruses evade host immune system?
- Low fidelity polymerases
- Lack proofreading
- Frequent reassortment
- Exchange nucleic acid segments with different strains of the same virus
What is the host of the mimivirus?
Acanthamoeba polyphaga
What are the virion shapes?
Helical
Polyhedral (many sided, icosohedral)
Binal (pleomorphic aka irregular shaped)
What is a capsid?
Protein shell enclosing nucleic acid, such as DNA, RNA, and enzymes
What is the capsid made of?
Capsomeres
Where do many viral envelopes come from?
The host cell
What do viral envelopes contain?
Glycoproteins required for infecting cells
What are naked viruses?
Without an envelope
Who discovered that viruses could be inactivated via boiling?
Martinus Beijerinck
Why are viruses not considered cells?
Composed of protein and nucleic acid
Required a host cell for replication***
What is zoonosis?
Viral pathogens can have an animal origin or host/reservoir
What are examples of viruses that “humanized” and can no longer infect animal hosts?
Measles and HIV
Where does influenza come from?
Birds and pigs
Where does Ebola come from?
Bats
Where do rabies come from?
Mammals
Where does SARS come from?
Civets
Where does Middle East Respiratory Syndrome come from?
Dromedary camels
Where does COVID-19 come from?
Unverified, but bats or pangolins are suspected
What doe viruses make us sick?
Host cells manipulated to produce viruses and not their usual function
Ex. changes in size, shape, inclusion bodies, altered DNA, cancerous transformation, inflammation
