Viroids Flashcards
1
Q
Nucleic acid or protein?
A
Only nucleic acid!
2
Q
Morphology
A
+ssRNA, circular, superhelical (extra protection), no structural proteins!
3
Q
Resistance
A
extremely strong (100°C for 30 min, UV and gamma radiation, disinfectants - no effect)
4
Q
pathogens
A
plant pathogens - only cultivated in plants (indirect effect on animals and humans by feed)
5
Q
way of infection
A
require injuries to the plants (by gardening tools, insects, etc.) to infect the plant cell, because the plant cell has both cell membrane and cell wall
6
Q
host spectrum
A
varies, no orphan viroid (all viroids cause clinical symptoms)
7
Q
Antigenic properties
A
not antigentic, because Ag=proteins (viroids do not have proteins) and because plants does not have an immune system
8
Q
Examples of viroids
A
- Potato spindle tuber viroid -> deformed potatoes
- Hop stunt viroid -> spots on leaves
- Coconut cadang-cadang viroid
