Viruses Biology 11 A. MacAskill
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
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
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
Complex Example: Bacteriophage • Virus which attacks Bacteria
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
Understanding viruses: Video During the video, answer the questions which were given!