Types of disease

• Pathogens cause communicable diseases and can infect both plants + animals
• Types of pathogen

  • bacteria
  • viruses
  • protists
  • fungi
• Bacteria produce toxins that damage cells and tissues
• Viruses live inside your cells + replicate themselves repeatedly causing a cell to burst
• Protists are eukaryotes
• Pathogens can be spread by

  • water
  • air
  • direct contact
• The 3 viral diseases

  • measles
  • HIV
  • TMV
• Measles is spread by droplets in the air from coughs and sneezes. You can be vaccinated against it at an early age.

  Symptom: red skin rash + fever

  Can lead to pneumonia, death and a brain condition called encephalitis.
• HIV is spread by sexual contact or evidence of bodily fluids.

  Symptoms: flulike

  Virus attacks immune cells weakening the immune system and can develop into AIDS.
• TMV (tobacco mosaic virus) affects many species of plant.

  Symptom: discoloured mosaic pattern on leaves

  Means plant can’t carry out photosynthesis as efficiently leading to stunted growth
• Viruses measly hairy tits

  Fungal rose

  Pro malaria

  Bake salmon go
• Rose black spot is a fungal disease that causes purple/black spots to form on the leaves of rose plants. Leaves turn yellow and drop off so less photosynthesis can happen.
• Rose black spot spreads by water and wind. It can be treated with fungicides and stripping the plant of affected leaves.
• Malaria is spread by the vector mosquitoes.

  Causes repeating episodes of fever and can be fatal.

  Can reduce spread by reducing breeding of vector. Can protect people with insecticides and mosquito nets.
• The bacteria salmonella causes food poisoning.

  Symptoms: fever, stomach cramps, vomiting, diarrhoea

  It is spread by eating contaminated food. Most poultry is vaccinated against it.
• Gonorrhoea is an STD and is spread by unprotected sex.

  Symptoms: painful urination, thick yellow or green discharge from vagina or penis

  Treat: penicillin (now less effective as increased resistance)

  Prevent: use condoms