Virus

• Virus:

  • Has a coat of fat
  • Inside the coat is the genetic material, made of DNA or RNA but not both

  The influenza/flu is a human disease caused by a virus.

  Pathogen - microorganisms that caused the disease
• Viruses only function inside a living organism;

  • They only reproduce inside a cell
  • The cell occupied by a virus is known as a host cell
  • When a virus enters a host cell, it uses its resources (food, enzymes) to reproduce
• If a person's immune system is healthy:

  • The DNA of a virus will set off alarms in the body. The body recognises that a foreign thing has entered it, and will try to kill it.
  • White blood cells can make antibodies that fit onto the spikes of the virus, immobilising the virus so that the white blood cells can engulf it, killing the cell.

  Antibiotics - medicines used to treat infections caused by bacteria and other pathogens
• Vaccination - using a harmless version of a disease to encourage the production of antibodies and white blood cells against the disease