General Virology

Question 1

What is a virus at the genetic level ?

Answer 1

Parasite

Question 2

The virus is ?

Answer 2

The smallest infectionus agents (20-300nm)

Question 3

Why viruses are obligatory intracellular ?

Answer 3

Because they have no metabolic activity

Question 4

What organisms can the virus infect?

Answer 4

All organisms (animals, plants, and bacteria).

Question 5

What is the name of the planet’s virus ?

Answer 5

Include complete viruses and Viroid (only nucleic acid ,without protein coat)

Question 6

How can i see the virus ?

Answer 6

Only by electron microscope, except (poxviruses)

Question 7

Are viruses can have both nucleic acids ?

Answer 7

No, it contains (DNA or RNA) never both

Question 8

The capsid is made of

Answer 8

Substance called capsomeres

Question 9

Functions of viral capsid

Answer 9

1_ protection.
2_ attachment.
3_ antigenic.
4_ morphology of virus (symmetry)

Question 10

The Genome is ?

Answer 10

Viral nucleic acid = the infectious part of the virus.

Question 11

STAGES OF VIRUS Replication

Answer 11

1_ Attachment or adsorption.
2_ Penetration (internalization) , (non-enveloped = endocytosis) or (enveloped = fusion).
3_ Uncoating.
4_ Eclipse.
5_ intracellular viral synthesis.
6_ Assembly (morphogenesis) nucleic acid + protein capsid = virions
7_ Release (lysis) or (buding).

Question 12

What are the ways to cultivate the virus?

Answer 12

1_ Cell culture (tissue culture).
2_ Embryonated eggs.
3_ Laboratory animals (intact animals).

Question 13

Fate of viral infections

Answer 13

1_ Inapparent or subclinical.
2_ Apparent infection (Disease).
3_ Persistent viral infections (chronic).
4_ Latent viral infections (dormant form).
5_ Slow viral infections (long incubation periods).