3 infection and response

• Pathogens


  Microorganisms such as viruses and bacteria that cause infectious diseases in animals and plants
• Pathogens


  • They depend on their host to provide the conditions and nutrients that they need to grow and reproduce
  • They frequently produce toxins that damage tissues and make us feel ill
• Avoiding diseases


  1. Reducing contact with pathogens

  2. Body uses barriers against pathogens
• Immune system


  Usually strong enough to destroy the pathogen and prevent disease
• Vaccination


  Enhances the body's natural system when at risk from unusual or dangerous diseases
• Antibiotics


  Developed since the 1940s and have proved successful against a number of lethal diseases caused by bacteria
• Many groups of bacteria have now become resistant to these antibiotics
• The race is now on to develop a new set of antibiotics