Viruses Flashcards
(12 cards)
Characteristics of a Virus?
- extremely small
- not really living
- obligate intracellular parasites
- only reproduce inside a living cell
- always associated with a disease
- can remain in a dormant shape
Why are viruses considered ‘not really living’?
They do not exhibit all characteristics of life.
What is an obligate intracellular parasite?
Can only survive inside cells of other organisms.
What is a host cell?
The living cell that a virus infects and uses to replicate itself.
What is a capsid?
The protein coat surrounding a virus’s genetic material, providing protection and aiding in the infection of host cells.
What is a genome?
The genetic material of a virus, which can be either DNA or RNA, used to hijack the host’s cellular machinery for replication.
What is a retrovirus?
A type of RNA virus that uses the enzyme reverse transriptase to convert it’s RNA into DNA, allowing integration into the host genome.
What is an antigen?
A foreign molecule, often present on viruses, that triggers an immune response in a host.
Why are viruses considered acellular?
Viruses are considered a cellular because they lack the basic structures of cells, such as a membrane, cytoplasm, and organelles.
The three shapes of viruses?
- Polyhedral (cubical)
- Helical (spiral)
- Complex (tadpole-like)
What is a viroid?
An infectious RNA particle that resembles a virus, but is smaller. It causes diseases in plants.
Why are viruses difficult to cultivate?
Because they must be grown in living host material.
