Viruses Flashcards
(10 cards)
1
Q
What are viruses
A
- non-cellular parasites that do not fall into any kingdom
- don’t grow, metabolize or divide but can duplicate
- unclear evolutionary history, no fossils
2
Q
Morphology
A
- non-cellular, no organelles and membranes
- contains a nucleic acid core and protein capsid
- may have more protein or phospholipid membranes from the host
- may contain proteins like enzymes
3
Q
How are capsids classified?
A
- Based on shape:
- helical: long and cylindrical, plant viruses
- icosahedral: spherical, polio, herpes
- enveloped: membrane derived from host, HIV
- head-and-tail: head like an icosahedral, tail like a helical
4
Q
What are Nucleic Acids?
A
- Core that holds the genome, codes for proteins not obtainable from the host
- vary based on type (RNA or DNA) and organization
- DNA viruses include chickenpox, hep B, herpes, HPV
- RNA viruses includes flu, hep C, measles, rabies, HIV
5
Q
How are viruses classified
A
- classified only by NA and capsid type
- Baltimore classification features how mRNA is produced in the replication process
6
Q
Plant Viruses
A
- cell wall impenetrable, require mechanical damage
- movement from cell to cell facilitated by modification of the plasmodesmata
- can be transmitted to offspring
7
Q
How are plant viruses transmitted?
A
- via infected sap, insects and other organisms, pollen
- horizontal transfer: plant to plant
- vertical transfer: parent to offspring
8
Q
Symptoms of plant viruses
A
- hyperplasia: tumor like growths
- hypoplasia: decreases cell growth, yellow areas
- necrosis: cell death
- malformed leaves
- black streaks on stems
- alteration of stem, leaf and fruit growth
- ring spots on leaves
9
Q
Animal Viruses
A
- no penetration, may even induce hosts cooperation
- non-enveloped: bind to host cell or create channels in membrane
- enveloped: bind or fuse to plasma membrane
10
Q
Types of Animal Viral Infections
A
- Acute: symptoms get worse for a short time and then removed via the immune system
- Chronic: long-term
- Intermittent: only active under certain conditions
- Asymptomatic: no symptoms in the host
