Possible Origin of Viruses

1
Possible Origin of Viruses

• Emman Perez
• Joey Torres
• II-Sampaguita

2
Virus?

• latin virus refers to poison and other noxious
  substances
• a small infectious agent that can replicate only
  inside living cells of organisms
• can infect ALL types of organisms regardless of
  size

3
Structure

• Very hard to see using normal microscope
• Most viruses have a diameter between 10-300
  nanometres
• Have four main morphological virus types
• Helical spiral shaped
• Icosahedral near spherical
• Envelope envelope themselves in modified cell
  membranes
• Complex possess extra structures such as
  protein tails and complex outer walls.

4
How did they start?

• Still unclear to most scientists
• Viruses do not leave any fossils
• They have to be untangled from their host cells
• 3 main Hypotheses
• Regressive hypothesis
• Cellular origin hypothesis
• Coevolution hypothesis

5
How do we spot viruses?

• Louis Pasteur was unable to find a causative
  agent for rabies
• Charles Chamberland
• Invented a filter which had pores smaller than
  bacteria
• Dmitry Ivanovsky
• Tobacco Mosaic Virus
• Martinus Beijerinck
• the filtered solution contained a new form of
  infectious agent

6
How to prevent viruses

• Vaccination
• Cheap and effective way of preventing infections
• Improves immunity
• Antiviral Drugs
• Nucleoside analogues
• DNA Chain Termination

7
References

• http//www.scientificamerican.com/article.cfm?ide
  xperts-where-did-viruses-come-fr
• http//en.wikipedia.org/wiki/Virus
• http//www.bookrags.com/research/evolutionary-orig
  in-of-bacteria-and-wmi/