Viruses - PowerPoint PPT Presentation

viruses n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Viruses PowerPoint Presentation
play fullscreen
1 / 11
Viruses
260 Views
Download Presentation
tallys
Download Presentation

Viruses

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Viruses Biology 11 A. MacAskill

  2. What is a virus? • Virus is the Latin word for Poison • A Virus does not fit the six kingdom classification • They lack the characteristics of living cells • Unlike all true organisms (even the most simple bacteria) viruses have no cellular structure • No Cell Membrane • No organelles

  3. Virus characteristics • Viruses have both non-living and living characteristics: • Non-living: Alone a virus is life-less • Living: Capable of reproduction with a host cell • Viruses do not require energy – or carry out other common life processes such as growth, respiration and metabolism

  4. Basic Virus Structure • Very verysmall - measured in nanometers (nm) • Two main parts: • Protein coat (a.k.a. capsid) • Core (contains DNA or RNA) • Viruses can be different shapes • Virus are specific to their host

  5. Helical Example – Tobacco Mosaic Virus

  6. Polyhedral Example:Rhinovirus( common cold)

  7. Complex Example: Bacteriophage • Virus which attacks Bacteria

  8. Viral replication: lytic Cycle

  9. Lytic or Lysogenic Cycle

  10. How Can Humans Avoid Viral Infections? • Vaccines: solutions that are prepared from viral components or inactivated viruses • An individual is injected with viral components, their body creates anti-bodies as if the virus is real. • These anti-bodies stay with us and as a result, a vaccinated person is immune to that disease

  11. Understanding viruses: Video During the video, answer the questions which were given!