80. VIRAL DISEASES IN ANIMALS

Question 1

1. What do Viruses do to their Host Cells?

Answer 1

• they damage or kill them

Question 2

2. What are four mechanisms in which the Virus can damage or kill their Host Cell?

Answer 2

1. Cell Lysis
2. Toxin Production
3. Toxic Macromolecules
4. Inhibition of the host Cell Replicative Machinery

Question 3

3. Define: Cell Lysis.

Answer 3

• this is kill the Host cell
• it happens when Hydrolytic Enzymes are released from
  Lysosomes

Question 4

4. Define: Toxin production.

Answer 4

• viruses cause the infected Host Cells to produce toxins
• these lead to disease symptoms in the Host Cell

Question 5

5. Define: Toxic Macromolecules.

Answer 5

VIRUSES CAN HAVE TOXIC MACROMOLECULES
- such as Viral Envelope proteins
- these will harm the Host Cell

VIRUSES ALSO HAVE VIRAL PROTEINS:
- these cause a change in the permeability of the Host
Cell’s Plasma Membrane
- this damages the Host Cell

Question 6

6. In which types of Viruses does Cell Lysis take place?

Answer 6

• Viruses that do not have an envelope

Question 7

7. In which type of Viruses does Toxin Production take place?

Answer 7

• Viruses that do not have an envelope
• Viruses that do have an envelope

Question 8

8. Which type of viruses have toxic macromolecules and viral proteins?

Answer 8

• viruses that have an Envelope

Question 9

9. Which type of viruses inhibit the host cell replication machinery?

Answer 9

• Viruses that do not have an envelope
• Viruses that do have an Envelope

Question 10

10. What are four examples of Double Stranded DNA Viruses (ds DNA)?

Answer 10

1. Adenovirus
   - non-enveloped
2. Papovirus
   - non-enveloped
3. Herpesvirus
   - enveloped
4. Poxvirus
   • enveloped

Question 11

11. What is one example of a Single Stranded DNA Virus (ss DNA)?

Answer 11

1. Parovirus
   - no envelope

Question 12

12. What is one example of a Double Stranded RNA Virus (ds RNA)?

Answer 12

1. Reovirus
   - no envelope

Question 13

13. What are four examples of Single Stranded RNA
    (ss RNA) Viruses?

Answer 13

1. Picornavirus
   - non-enveloped
2. Coronavirus
   - enveloped
3. Flavivirus
   - enveloped
4. Togavirus
   - enveloped

NB:
- these viruses are Positive Sense viruses
- they have a 5’-3’ Orientation
- they run in the same direction as the mRNA

Question 14

14. What are four examples of Single Stranded RNA
    (ss RNA) Viruses that is a template for mRNA Synthesis?

Answer 14

1. Filovirus
   - enveloped
2. Orthomyxovirus
   - enveloped
3. Paramyxovirus
   - enveloped
4. Rhabdovirus
   - enveloped

NB:
- these viruses are Negative Sense viruses
- they have a 3’-5’ Orientation
- they run in the opposite direction of the mRNA

Question 15

15. What is one example of a Single Stranded RNA
    (ss RNA) Viruses that is a template for DNA Synthesis?

Answer 15

1. RETROVIRUS
   - enveloped

Question 16

16. Define: Vaccines.

Answer 16

• these are a form of preventative measure

IT IS WHEN:
- harmless derivatives of pathogenic microbes are
injected into the body
- these will stimulate the immune system

THE IMMUNE SYSTEM WILL THEN:
- create a defensive system against the harmful
pathogen

Question 17

17. What do Vaccines commonly consist of?

Answer 17

• dead pathogens
• inactivated pathogens
• the products of dead or inactivated pathogens

THESE PRODUCTS INCLUDE:
- proteins
- nucleic acids

Question 18

18. What can vaccines prevent?

Answer 18

• they can prevent certain viral illnesses
• they can prevent certain bacterial illnesses
• they act as important control measures

Question 19

19. How do vaccines act as important control measures?

Answer 19

• they provide protection from viruses
• viruses cannot be treated by antibiotics
• they can be partially treated by antiviral drugs

Question 20

20. What can be said about the prevention of RNA viruses?

Answer 20

• there cannot be a permanent vaccine for RNA viruses
• there can be no herd immunity built up against them
• this is because they are ever changing
• they also mutate rapidly

EXAMPLE:
- HIV