pathogen type knowledge test

• What is a disease?

  an illness or disorder of the body or mind that leads to poor health
• What are communicable diseases caused by, how do they spread?

   pathogens and are transmissible (can be spread between individuals within a population)
• Examples of infectious diseases?

  Cholera

  Malaria

  HIV/AIDS

  Tuberculosis (TB)
• What are the main four types of pathogen?

  Bacteria

  Viruses

  Fungi

  Protoctists
• Bacteria?

  • Bacteria are a diverse range of prokaryotic organisms
  • Some bacteria are non-pathogenic (they do not cause any disease or damage) while others are pathogenic
  • Pathogenic bacteria do not always infect the hosts of cells, they can remain within body cavities or spaces
• What diseases are bacteria responsible for?


  Tuberculosis

  Ring rot in potato plants

  Bacterial meningitis in humans
• Tuberculosis- bacteria?


  • The bacteria infect the lungs, causing a chronic cough and bloody mucus
  • It is a disease often associated with poor hygiene and sanitation
• Bacterial meningitis in humans?


  • Very few bacteria can cross the barrier created by the meninges (the tissue that surrounds the brain and spinal cord) however N. meningitidis crosses this barrier to cause inflammation
  • Inflammation of the meninges causes symptoms such as fever, headache, neck stiffness and a characteristic rash
• Ring rot - bacteria?


  • The bacteria infect the vascular tissue and prevent the transport of water, causing the plant to wilt and die
  • The infection spreads into the potato tubers where the vascular tissue is arranged in a ring, producing the characteristic black ring of rot
• Viruses?


  • Viruses do not have a cellular structure
  • This means they can't respire, produce ATP, replicate genetic material or synthesise protein
  • They infect host cells and hijack their machinery to replicate their own genetic material and proteins
• What diseases do viruses cause?

  HIV/AIDS

  Influenza

  Tobacco mosaic virus (TMV)
• Tobacco mosaic virus (TMV)?


  plant virus

  • The first virus ever discovered was the Tobacco Mosaic Virus (TMV)
  • TMV infects several plant species
  • It causes a distinct yellowing of the leaves which produces a mosaic pattern
• Influenza - caused by virus pathogen?

  • 3 different influenza viruses infect humans to cause the flu
  • Influenza A, influenza B and influenza C infect the cells that line the airways
  • They cause a high temperature, body aches and fatigue
  • Influenza A is the virus that causes the most cases of flu globally
  • It has a capsid that surrounds 8 single-stranded molecules of RNA
• HIV/AIDS - caused by virus pathogen?

  • The human immunodeficiency virus (HIV) infects specific cells of the immune system
  • It is an enveloped retrovirus
  • The viral enzyme reverse transcriptase produces single-stranded DNA from its viral RNA
  • DNA polymerase synthesises double-stranded DNA from this single-stranded DNA
  • The double-stranded DNA is inserted into the host DNA and can remain inactive for many years
  • Once activated the DNA provirus is used to synthesise new viruses
• Protoctista?

  • Protists are unicellular eukaryotes
• What diseases are caused by protoctists?


  Potato/tomato late blight

  Malaria
• Malaria- protoctists?

  • Plasmodium falciparum is a protist that causes severe forms of malaria in humans
  • The parasite is spread by mosquitoes
  • Infected individuals experience fever, chills and fatigue
• Potato/Tomato late blight- protoctist?

  • The pathogen is unusual as it has some fungal characteristics
  • It is transmitted via spores
  • The first signs of potato blight are small, dark brown marks on the leaves which quickly increase in size and number
  • The protist destroys potato and tomato crops leaving them completely inedible
• Fungi?

  • Fungi have a similar structure to plants
  • Their eukaryotic cells have cell walls and large central vacuoles
  • However, instead of being made of separate cells, their bodies consist of filaments known as hyphae
  • These hyphae form a network and spread throughout a host/soil
  • Fungal diseases are much more common in plants than animals
• What are diseases caused by fungi?

  Black sigatoka

  Ringworm

  Athlete's foot
• Black sigatoka?


  • Black Sigatoka is a fungal disease in bananas
  • It spreads through the leaves of the plant, reducing its ability to photosynthesise
  • The lack of photosynthesis causes parts of the leaf to die; producing black streaks
  • Eventually, the whole leaf dies
• what is a pathogen?

  a disease-causing micro-organism