Communicable disease

• Pathogens are microorganisms that enter the body and cause disease, they are communicable that can be easily spread. Plants and animals can be infected by pathogens.
• Bacteria

  • very small cells which can rapidly reproduce inside of your body
  • They can make you feel ill by producing toxins that damage your cells and tissues
• Viruses

  • not cells but they still rapidly reproduce inside of your body
  • they live inside of cells and replicate themselves using the cell machinery to produce many copies of themselves, the cells will burst releasing all the new viruses
  • cell damage is what makes you feel ill
• Protist

  • are all eukaryotes and most of them are single-celled
  • some are paracites, they live on/inside other organisms and can cause damage - often transferred by a vector
• Fungi

  • some are single celled, others have a body which is made up of hyphae
  • grow and penetrate human ski and the surface of plants causing diseases
  • hyphae can produce spores which can spread to other plants and animals
• Pathogens can spread in different ways

  • water - drinking or bathing in dirty water - cholera
  • air - carried and breathed in the air - flu
  • direct contact - touching contaminated surfaces - athletes foot