Communicable Diseases

• Define Good Health:

  Complete physical, social, and mental well-being free from illness
• Define Pathogen:

  A microorganism that causes disease
• State types of pathogens:

  • Virus
  • Bacteria
  • Fungi
  • Protist
• In plants, the bacteria often live in the vascular bundles
• Bacteria do not require a host to survive whereas viruses are entirely dependent on their hosts and cannot survive without them
• What are the two types/means of transmissions?

  • Direct
  • Indirect
• Define Mycelium:

  The infected vegetative part of a fungus formed from hyphae
• Define Hyphae:

  A network of fine white filaments which forms mycelium
• Define Tuberculosis (TB):

  A bacterial disease that damages lung tissue and weakens the immune system
• Define Bacterial Meningitis:

  A bacterial disease that infects the meninges
• Define Meninges:

  The three layers of membranes that protect the brain and spinal cord
• Define Ring rot (in plants):

  A bacterial disease that decays the vascular tissues in potatoes
• Define HIV/AIDS:

  A virus that destroys T helper cells, weakens the immune system and makes an individual more susceptible to infections and can lead to AIDS
• What does HIV stand for?

  Human Immunodeficiency Virus
• What does AIDS stand for?

  Acquired Immunodeficiency Syndrome
• Define Influenza:

  A virus that destroys ciliated epithelial cells in the gaseous exchange system, exposing the airways to secondary infection
• State four secondary infections due to influenza:

  • fever
  • headache
  • muscle pain (myalgia)
  • fatigue
• Define Tobacco mosaic virus (TMV):

  A virus that causes discolouration of leaves in tobacco plants
• Define Black sigatoka(bananas):

  A fungal disease that causes black spots on leaves and stems
• How does black sigatoka cause black spots on leaves?

  The hyphae from a mycelium penetrates and digest the leaf cells
• Define Blight (tomatoes and potatoes):

  A disease that damages leaves and potato tubers
• Define Ringworm (cattle):

  A fungal disease that affects the skin
• Define Athlete's foot (humans):

  A fungal disease that makes the skin of feet itching and scaling
• Define Malaria:

  A disease in the blood spread by mosquitoes caused by protoctista
• Name three diseases caused by bacteria:

  • Tuberculosis
  • Bacterial meningitis
  • Ring rot
• Name three diseases caused by viruses:

  • HIV/AIDS
  • Influenza
  • Tobacco Mosaic
• Name three diseases caused by fungi:

  • Black sigatoka
  • Ringworm
  • Athlete's foot
• Name three diseases cause by protoctista:

  • Malaria
  • Dysentery
  • Blight
• Define Dysentery:

  An intestinal disease that causes diarrhea containing blood or mucus caused by protoctista
• Name an enzyme the hyphae releases in fungus infections:

  Cellulase
• What does the enzymes cellulases causes?

  Decay
• What do the hyphae release to help them grow and cause decay?

  Spores and enzymes
• Why do bacteria and fungi live in the vascular tissues of plants?

  There is a good supply of water and nutrients
• Define Retrovirus:

  A type of virus that carries RNA to make a complementary DNA copy which is then integrated into a host cell’s DNA.
• What type of cells are bacteria?

  Prokaryotic
• Name six examples of a viral infection:

  • HIV
  • influenza
  • measles
  • mumps
  • rubella
  • chicken pox
• Give examples of the symptoms of TB:

  • coughing
  • fever
  • weight loss
• Define Transmission:

  The process by which a pathogen is transmitted from an infected host to a susceptible host
• Define Direct Transmission:

  The transmission of a pathogen directly from an infected host to a susceptible host
• State the means of transmission:

  • Direct physical contact
  • Faecal-oral
  • Water droplets
  • Spores
  • Vector