pathogens (viruses, bacteria and fungi)

• What is a pathogen?

  A microorganism that causes a disease
• What are the four main types of pathogens?

  • Viruses
  • Bacteria
  • Fungi
  • Parasites
• Why are viruses considered not alive?

  They do not complete all seven life processes
• What are the seven life processes that organisms complete?

  • Movement
  • Respiration
  • Sensitivity
  • Nutrition
  • Excretion
  • Reproduction
  • Growth
• What term is used to describe different types of viruses?

  Strains
• What is the genetic material of most viruses made of?

  Short length of DNA
• What surrounds the genetic material of a virus?

  A protein coat
• Why can viruses be difficult to treat?

  They mutate quickly
• How long can viruses survive outside a host?

  For long periods of time
• What happens when a virus infects a suitable host cell?

  It replicates itself thousands of times
• How do viruses replicate within a host cell?

  They replicate their DNA and protein coats
• What happens to the host cell after viral replication?

  The cell bursts and releases new viruses
• How quickly can the Norovirus replicate in a host cell?

  As quick as twelve hours
• How long can the replication process take for Ebola?

  Several days
• Why can't viral infections be treated with antibiotics?

  Viruses do not have cell walls
• Where are viruses found in relation to host cells?

  Inside host cells
• What are the steps of viral replication?

  1. Virus attacks a cell
  2. Inserts its genes
  3. Tells the nucleus to copy its genes
  4. New viruses are made
  5. Cell bursts, releasing new viruses
  6. Process repeats
• Are all bacteria pathogens that cause disease?

  No, many bacteria are useful
• What type of organisms are all bacteria classified as?

  Prokaryotes
• What cellular structures do bacteria lack?

  Nucleus, chloroplast, and mitochondria
• How do bacteria differ from viruses in terms of cellular structure?

  Bacteria are living cells, viruses are not
• What do bacteria release as they reproduce?

  Toxic waste products
• How do bacteria reproduce?

  By binary fission
• How might you calculate the number of bacteria produced over time?

  Using the formula for binary fission
• Is yeast a single-celled or multicellular fungus?

  Single-celled
• Why is yeast considered economically important?

  It is used to make bread and beer
• What type of fungi are mushrooms classified as?

  Multicellular fungi
• What do fungal cells contain that makes them eukaryotic?

  A nucleus
• What are hyphae in fungi?

  Structures that can penetrate skin
• What condition can hyphae cause when they penetrate the skin?

  Athlete's foot
• What are protists classified as in terms of cellular structure?

  Eukaryotic microorganisms
• How is malaria transmitted?

  By female Anopheles mosquitoes
• What do female Anopheles mosquitoes carry that spreads malaria?

  The Plasmodium protist
• What role do mosquitoes play in the transmission of malaria?

  They are vectors for the disease
• What are the symptoms of malaria?

  Fever, sweats, chills, headaches, vomiting, diarrhea
• How many people are infected with malaria each year?

  200 million
• What percentage of malaria-infected individuals may die from the disease?

  Up to half
• What recent development has been made regarding malaria?

  A vaccine has been developed
• How can malaria infection be prevented?

  By avoiding mosquito bites
• What methods do people use to avoid mosquito bites?

  Sleeping under nets and using repellents