Virology

Question 1

What features distinguish viruses from other organisms

Answer 1

1. Obligate intracellular parasite
2. No cell structure
3. Made of DNA or RNA but never both
4. Surrounded by a protein coat (capsid)
5. Contain genetic info for replication but need host to complete
6. May contain an envelope

Question 2

How are viruses classified

Answer 2

1. Type and structure of nucleic acid
2. replication strategy
3. Type of symmetry - helical vs icosahedral
4. Enveloped or not

Question 3

Attachment

Answer 3

Virion and host cell wall bind

Question 4

Penetration

Answer 4

Virion passes from surface of host cell to the cytoplasm, endocytosis or fusing with membrane

Question 5

Uncoating

Answer 5

virion capsid is removed, DNA RNA released

Question 6

Synthetic period

Answer 6

DNA/RNA synthesized, uses host to complete

Question 7

Maturation and release

Answer 7

Components of viral progeny are assembled and leave the cell

Question 8

Chronic viral infections

Answer 8

Prolonged, low grade viral activity, bouts of high activity

Question 9

Latent viral infections

Answer 9

Persistent infection where the virus is never cleared. Pt will have for the rest of life. Periods of no viral reproduction

Question 10

Slow infections

Answer 10

Persistent low level viral replication. Gradually increases over time and often no symptoms seen

Question 11

Carrier states

Answer 11

Period of low viral replication during a persistent infection . Host shows little to no signs, virus can still shed even when symptoms are not present