Significance

Question 1

Give the two forms of virus existence

Answer 1

• Virion
• Vegetative virus

Question 2

Virion

Answer 2

• Inert particles transferring genetic information
• 20-300nm
• Contain:
  
  • DNA/RNA
  • Protein
  • Lipid

Question 3

Vegetative virus

Answer 3

The infected cell

Question 4

Viral reproduction

Answer 4

• Multiplication: 10³-10⁶ virion_{/host cell}
• No energy production/protein synthesis enzymes
• No nucleic acid replicating enzymes
• Cell parasites - ‘infectious genes’

Question 5

Emerging new virus examples

Answer 5

• Zika
• Influenza
• Ebola
• MERSV
• HIV
• SARSV

Question 6

Orphan viruses

Answer 6

Cause infection but no disease

Question 7

Most viruses of eukaryotes probably have been evolved from…

Answer 7

Prokaryotic viruses

(Bacteriophages)

Question 8

What is notable about the phylogeny of viruses?

Answer 8

They do not fit into the phylogenetic tree of living creatures

Question 9

Cell degeneration theory of virus evolution

Answer 9

• Cells lost their independence
• Outside of the cell only carries the information

Question 10

Runaway cell components theory of virus evolution

Answer 10

• mRNA → ssRNA virus
• Chromosome-fragment → dsDNA virus

Question 11

Similarities in the genome of the virus and the host cell

Answer 11

Runaway intermediate products of viral multiplication or evolution from ancient nucleic acids

Question 12

Viruses represent …% of the biomass

Answer 12

10%