Communicable Diseases and Pathogens

• What are the four main categories of pathogens?

  Bacteria, viruses, fungi, and protoctista
• What is a pathogen?

  A microorganism that can cause disease
• What is the organism that a pathogen infects called?

  The host
• How can communicable diseases be spread?

  Between organisms of the same or different species
• What is bacterial meningitis an example of?

  A communicable disease
• What do pathogenic bacteria release that can damage host cells?

  Toxins
• What type of cells are bacteria?

  Prokaryotic cells
• Where is the genetic material found in bacteria?

  In the cytoplasm, not in a nucleus
• What is the chemical found in bacterial cell walls?

  Peptidoglycan
• How do bacteria cause symptoms of disease?

  By releasing toxins that damage host cells
• What is a key feature of viruses?

  They cannot reproduce outside of a host cell
• What do viruses consist of?

  Genetic material and a protein capsid
• What do attachment proteins on viruses do?

  Allow the virus to attach to host cells
• What happens when a virus enters a host cell?

  It copies itself using the host's enzymes
• How do fungi obtain nutrients?

  By releasing enzymes to digest surrounding material
• What is an example of a fungal disease in humans?

  Athlete's foot
• How do fungi reproduce?

  By releasing a large number of spores
• What can pathogenic fungi do to plants?

  Reduce photosynthesis and crop yield
• What are protoctista also known as?

  Protista
• What disease does Giardia cause?

  Diarrhea
• How is Plasmodium transmitted?

  By mosquitoes
• What are the main characteristics of bacteria?

  • Prokaryotic cells
  • Genetic material in cytoplasm
  • No membrane-bound organelles
  • Surrounded by a peptidoglycan cell wall
• What are the main characteristics of viruses?

  • Much smaller than bacteria
  • Non-living, no cellular structure
  • Consist of DNA or RNA in a capsid
  • Cannot reproduce outside a host cell
• What are the main characteristics of fungi?

  • Eukaryotic organisms
  • Can be unicellular or multicellular
  • Obtain nutrients by digesting surrounding material
  • Reproduce by releasing spores
• What are the main characteristics of protoctista?

  • Eukaryotic organisms
  • Can act as pathogenic parasites
  • Examples include Giardia and Plasmodium