84. NON CONVENTIONAL VIRUSES

Question 1

1. What are two types of Non-Conventional Viruses?

Answer 1

1. Viroids
2. Prions

Question 2

2. Define: Viroids.

Answer 2

• this is a virus that does not have a protein capsid
• it only has nucleic acid
• this nucleic acid is infectious
• it replicates in the tissue

VIROIDS:
- are plant pathogens

Question 3

3. Define: Prions.

Answer 3

• this is a virus that does not have nucleic acid
• it has a protein and a protein capsid only
• these small proteins are infectious
• they replicate in the tissues

PRIONS:
- are animal pathogens

Question 4

4. List two characteristics of Viroids.

Answer 4

1. They are small circular RNA molecules
2. They infect plants
   - they disrupt their growth

Question 5

5. List 4 characteristics of Prions?

Answer 5

1. They are slow acting
2. They are indestructible
3. They are infectious proteins
4. They cause serious Central Nervous System infections

Question 6

6. How do Prions propagate?

Answer 6

• they convert normal proteins
• into the prion version of the protein
• they will form larger and larger prions in the
  tissues

THE NORMAL PROTEIN WILL LOSE ITS FUNCTION:
- since it undergoes a shape change

Question 7

7. What are some examples of Prion Diseases?

Answer 7

1. Spongiform Encephalitis
2. Scrapie Disease in Sheep
3. Mad Cow disease
4. Creutzfeldt-Jakob disease in humans

Question 8

8. What is Spongiform Encephalitis?

Answer 8

• the brain will form holes like a sponge
• it will cause brain infections
• the brain will shrink
• the brain will deteriorate rapidly

Question 9

9. What is Mad Cow disease?

Answer 9

• this infects cattle

IT IS TRANSMITTED TO HUMANS:
- when we eat contaminated beef
- cooking does not destroy prions

THIS RESULTS IN:
- Creutzfeldt- Jacob disease (CJD) in humans
- this is very resistant

Question 10

10. What is Creutzfeldt-Jacod Disease?

Answer 10

• this is a Fatal Central Nervous System infection
• it is caused by Prions

Question 11

11. What are the symptoms of Creutzfeldt-Jacod Disease?

Answer 11

• ataxia
• memory loss
• convulsions
• coma

Question 12

12. How many known types of viral disease affect plants?

Answer 12

• over 2 000 types
• most plant viruses have a RNA genome

EXAMPLE:
- TMV

Question 13

13. What are the symptoms that plants have when they have a viral disease?

Answer 13

• spots on the leaves and fruits
• stunted growth
• damage to the flower
• damage to the roots

Question 14

14. Does this table make sense?

Answer 14

• yes

Question 15

15. Does this table make sense?

Answer 15

• yes

Question 16

16. Answer this question.

Answer 16

• B

Question 17

17. What is the most likely patient diagnosis?

Answer 17

• a Common Cold

Question 18

18. Which virus categories cause these symptoms?

Answer 18

• Adenovirus
• Rhinovirus
• Enterovirus
• Corona Virus