Chapter 1: An Invisible World – Study Guide (BIOL 2420)

Key Terms

• Acellular: Not made of cells (e.g., viruses)
• Bacteriology: Study of bacteria
• Binomial nomenclature: Two-name system (Genus + species) for naming organisms
• Domain: Highest taxonomic level (Bacteria, Archaea, Eukarya)
• Eukaryote: "You" are eukaryotic = has nucleus and organelles
• Helminth: Parasitic worms (multicellular eukaryotes)
• Immunology: Study of immune system
• Microbe / Microorganism: Tiny living things, too small to see unaided
• Microbiology: Study of microscopic organisms
• Mycology: Study of fungi
• Parasitology: Study of parasites
• Pathogenic: Disease-causing
• Phylogeny: Evolutionary relationships tree
• Prokaryote: No nucleus (e.g., bacteria, archaea)
• Protozoology: Study of protozoa
• Taxonomy: Naming and classifying organisms
• Virology: Study of viruses

Key Concepts

• Are all microbes harmful?
  • Most are beneficial: digest food, make vitamins, decompose waste, produce oxygen, and make food (e.g., yogurt).
• How did ancient people suspect microbes existed?
  • Spoiled food, disease transmission, fermentation hinted at "invisible agents."
• Antonie van Leeuwenhoek
  • Known as “Father of Bacteriology & Protozoology”
  • Created simple microscopes
  • First to see bacteria & protozoa, calling them “animalcules”
• Phylogenetic Tree
  • A "family tree" showing how organisms are related based on genetics, anatomy, biochemistry, and evolution.
• Taxonomy
  • System to classify and name organisms.
  • Taxonomic levels: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
  • Mnemonic: Dear King Philip Came Over For Good Spaghetti
  • Genus + Species for naming (e.g., Escherichia coli)
  • System by Carl Linnaeus
  • Species names formatted: Italicized, Genus capitalized, species lowercase (e.g., Staphylococcus aureus)
• Three Domains:
  • Bacteria (prokaryotes)
  • Archaea (prokaryotes)
  • Eukarya (eukaryotes: animals, fungi, protozoa, plants)
  • Proposed by Carl Woese
• Viruses
  • Not in any domain, as they are acellular.
• Bergey’s Manual
  • For classifying and identifying bacteria

Major Groups of Microorganisms

• Bacteria
  • Prokaryotic, Unicellular (e.g., E. coli)
• Archaea
  • Prokaryotic, Unicellular (e.g., Halobacterium)
• Fungi
  • Eukaryotic, Uni or Multicellular (e.g., Yeasts, molds)
• Protozoa
  • Eukaryotic, Unicellular (e.g., Amoeba)
• Algae
  • Eukaryotic, Uni or Multicellular (e.g., Diatoms, seaweed)
• Helminths
  • Eukaryotic, Multicellular (e.g., Tapeworms, roundworms)
• Viruses
  • Acellular, Neither (e.g., Influenza virus)

Fields of Microbiology

• Bacteriology: Study of bacteria
• Mycology: Study of fungi
• Protozoology: Study of protozoa
• Parasitology: Study of parasites
• Virology: Study of viruses
• Immunology: Study of immune system

Suggested Review Questions from OpenStax

• Multiple Choice: #1, 3, 6, 8–14
• Fill-in-the-Blank: #18, 20–25
• Short Answer: #27–29
• Critical Thinking: #36–39

(Answers available in textbook or can be explained upon request!)