pathogens

• what is a pathogen?

  a microorganism that causes infectious diseases
• a pathogen is..

  a communicable disease
• the 4 types of pathogens

  • bacteria
  • virus
  • protist
  • fungi
• how many people in the uk get food poisoning every year?

  300000
• once in the human body, bacteria...


  reproduce very rapidly
• how often can bacteria divide?


  every 20 minutes
• bacteria release...


  harmful chemicals called toxins
• what do toxins do?


  damage tissues making us feel ill
• viruses cannot...


  reproduce by themselves, and can only reproduce inside a host cell
• how does a virus reproduce inside a host cell?

  • first, the virus invades the host cell
  • next, the virus reproduces inside the host cell. this is very damaging, and if the virus leaves the cell it could burst and the cell could open and die
• how are pathogens spread?

  • spread in the air, eg water droplets
  • directly in water, eg cholera
  • direct contact, eg HIV
• how to prevent the spread of pathogens

  • washing hands and basic hygiene
  • drinking clean water
  • using a condom during sexual intercourse
  • vaccinations
• how is drinking water cleaned in the uk?

  the water contains chlorine, killing microbes