Communicable disease

• pathogens

  microorganisms that enter the body and cause disease
• bacteria


  small cells which reproduce rapidly inside your body and damage your cells and tissue
• viruses


  they are not cells - they are smaller than bacteria. they damage your cells which is what makes you feel ill
• protists


  single celled eukaryotic cells. parasites are a type of protist - usually carried to the organism by a vector e.g moquito
• types of pathogen

  • bacteria
  • virus
  • protist
  • fungi
• how can pathogens spread

  • water
  • air
  • dirct contact
• types of viral diseases

  • measles - spread by droplets of an infected person
  • HIV - spread by sexual contact or bodily fluids - flu-like symptoms
  • tobacco mosaic virus - affects many species of plants - leaves become discoloured and cause mosaic patterns - cant carry out photosynthesis
• black rose spot


  fungal disease. causes purple or black spots to develop on the leaves of rose plants - this means less photosynthesis can happen.
• mararia


  caused by a protist. mosquitos are common vectors of malaria
• bacterial diseases

  • salmonella
  • gonorrhoea
• salmonella


  a type of bacteria that causes food poisoning. can cause fever, stomach cramps, vomiting and diarrhoea. you can get it by ingesting contaminated by salmonella
• gonorrhoea


  STD - bacterial disease - pain when they urinate - thick discharge - patients take antibiotics and use barrier methods during intercource