Untitled Quiz
48 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which characteristic does NOT define a microbe?

  • Being microscopic
  • Being unicellular
  • Being able to be seen with the naked eye (correct)
  • Being able to reproduce

    • What distinguishes fungi from many other types of microbes?

  • Fungi are primarily aquatic organisms.
  • Fungi are always unicellular.
  • Fungi can be macroscopic and multicellular. (correct)
  • Fungi cannot reproduce.

    • Which of the following statements is true regarding the sizes of microbes?

  • All microbes can be seen without a microscope.
  • Some fungi are macroscopic and may be multicellular. (correct)
  • All bacteria are microscopic and unicellular.
  • All algae are multicellular organisms.

    • What organism classification system did Carl Woese and his colleagues propose?

    <p>Three-domain system</p> Signup and view all the answers

    Why is it incorrect to categorize all microbes as unicellular?

    <p>Many fungi and algal forms are multicellular.</p> Signup and view all the answers

    What misconception about microbes may arise when considering their visibility?

    <p>All microbes can be observed without special tools.</p> Signup and view all the answers

    Which of the following organisms belongs to the domain Eucarya?

    <p>Protozoa</p> Signup and view all the answers

    What technique did Woese use to identify the relatedness of microbes?

    <p>Ribosomal nucleic acid analysis</p> Signup and view all the answers

    How can molds be classified based on their visibility?

    <p>Molds are macroscopic and can be seen with the naked eye.</p> Signup and view all the answers

    Which statement about the characteristics of microbes is accurate?

    <p>Some microbes, like yeasts, are unicellular.</p> Signup and view all the answers

    Which two groups of organisms are considered prokaryotic in the Woese classification system?

    <p>Bacteria and Archaea</p> Signup and view all the answers

    What historical concept does the Woese classification system challenge?

    <p>Distinct separation of organisms into eukaryotes and prokaryotes</p> Signup and view all the answers

    Which of the following is NOT a common misconception about microbes?

    <p>Microbes can include macroscopic organisms.</p> Signup and view all the answers

    Which of the following is NOT a domain in the Woese classification system?

    <p>Protozoa</p> Signup and view all the answers

    What type of organisms does the domain Archaea primarily consist of?

    <p>Extremophiles</p> Signup and view all the answers

    What did Woese's analysis of ribosomal nucleic acid help to determine?

    <p>The evolutionary history and relatedness of organisms</p> Signup and view all the answers

    What unique ability does Deinococcus radiodurans possess that allows it to withstand high levels of gamma radiation?

    <p>It can repair its damaged DNA.</p> Signup and view all the answers

    How many new organisms were discovered in the human mouth by scientists at Stanford University?

    <p>Thirty-seven</p> Signup and view all the answers

    Why had the new microbes in the human mouth remained unknown prior to recent studies?

    <p>Traditional culture methods did not allow their growth.</p> Signup and view all the answers

    What do the National Science Foundation and the American Society for Microbiology aim to achieve with their global microbial survey?

    <p>To identify and catalog microbes that make up the biosphere.</p> Signup and view all the answers

    What is the estimated percentage of microbial population that has been identified so far?

    <p>Less than 2%</p> Signup and view all the answers

    What intriguing question about Earth's origins remains speculative?

    <p>The origins of life on Earth.</p> Signup and view all the answers

    What term is used to describe microbiologists who extract DNA from dental plaque?

    <p>Plaque pickers</p> Signup and view all the answers

    What is the estimated diversity of ecosystems in the human mouth compared to other environments?

    <p>Rivals the biodiversity of tropical rainforests.</p> Signup and view all the answers

    What is the defining characteristic of prions that distinguishes them from viruses?

    <p>Prions lack nucleic acids entirely.</p> Signup and view all the answers

    What disease is NOT caused by prions?

    <p>HIV/AIDS</p> Signup and view all the answers

    What is the significance of the 1997 Nobel Prize awarded to Stanley Prusiner?

    <p>It legitimized prions as separate entities.</p> Signup and view all the answers

    How are viruses characterized in relation to their replication?

    <p>They are obligate intra-cellular parasites.</p> Signup and view all the answers

    Which of the following statements about viruses is incorrect?

    <p>Viruses can be observed with a light microscope.</p> Signup and view all the answers

    What do prions primarily convert in the body?

    <p>Normal proteins into disease-causing proteins.</p> Signup and view all the answers

    Which of the following is NOT a characteristic of viruses?

    <p>They contain both RNA and DNA.</p> Signup and view all the answers

    Where do prions primarily exist in the body?

    <p>In the brain.</p> Signup and view all the answers

    What is a major distinguishing feature between procaryotic and eucaryotic cells?

    <p>Presence of a nuclear membrane</p> Signup and view all the answers

    Most bacteria are typically classified as which of the following?

    <p>Heterotrophs</p> Signup and view all the answers

    Which unit of measurement is the smallest?

    <p>Nanometer</p> Signup and view all the answers

    Which of the following are classified as obligate intracellular parasites?

    <p>Viruses</p> Signup and view all the answers

    Which of the following does not contain nucleic acid in its structure?

    <p>Prions</p> Signup and view all the answers

    The five-kingdom system of taxonomy is attributed to which scientist?

    <p>Whittaker</p> Signup and view all the answers

    According to Woese, how did Eucarya arise?

    <p>From Archaea</p> Signup and view all the answers

    Which organisms do not require organic compounds for growth?

    <p>Autotrophs</p> Signup and view all the answers

    What defines viruses and prions in terms of biological classification?

    <p>They are not classified as procaryotic or eucaryotic.</p> Signup and view all the answers

    Which of the following statements about microbial classification is accurate?

    <p>Woese's classification system is based on rRNA analysis.</p> Signup and view all the answers

    How do microbes adapt to extreme ecological conditions?

    <p>By developing diverse metabolic strategies.</p> Signup and view all the answers

    What distinguishes procaryotic bacteria from other microbes?

    <p>They are unicellular and lack membrane-bound organelles.</p> Signup and view all the answers

    What is one misconception regarding the terms 'bugs' and 'germs'?

    <p>They are collective terms for diverse microbial agents.</p> Signup and view all the answers

    What major characteristic do all organisms, including microbes, need to fulfill?

    <p>The requirement for energy.</p> Signup and view all the answers

    What is the historical trend in the classification of microbes?

    <p>Recognizing the uniqueness of different microbial groups.</p> Signup and view all the answers

    Which of the following best describes the origin of microbes on Earth?

    <p>They emerged in extreme environments and spread out.</p> Signup and view all the answers

    Study Notes

    The Microbial World

    • Microbes are incredibly small, often invisible without a microscope
    • Many microbes are not harmful pathogens
    • Microbes are classified into six groups: bacteria, viruses, protozoans, unicellular algae, fungi, and prions
    • Cells are the basic unit of life.
    • All organisms are either unicellular or multicellular
    • All cells are fundamentally alike in reference to structure and metabolism
    • Cells arise only from previously existing cells

    Microbial Principles

    • Cell theory postulates that: All organisms are composed of cells; all cells come from pre-existing cells and all cells are fundamentally alike in structure and metabolism
    • Metabolic diversity is a key characteristic of living systems
    • Organisms need energy to survive.
    • Autotrophs make their own food
    • Heterotrophs derive energy from consuming other organisms
    • Organisms require oxygen in varying levels to survive, categorized as aerobes (require oxygen), anaerobes (do not require oxygen), and facultative anaerobes (better in oxygen environments, but can survive without it)

    Microbes

    • Microbes are defined as biological agents that are generally too small to be seen without a microscope
    • Microbes are either prokaryotic or eukaryotic
    • Prokaryotes lack a membrane-bound nucleus and other organelles
    • Eukaryotes have a membrane-bound nucleus and other membrane-bound organelles
    • Classification of microbes has evolved over time
    • The modern approach to classification is based on the three-domain system (Bacteria, Archaea, and Eukarya)
    • Microbes, despite their small size, play essential environmental functions

    Procaryotic and Eucaryotic Cell

    • Prokaryotic cells are simpler in structure than eukaryotic cells, with no membrane-bound nucleus, and no organelles
    • Eukaryotic cells are more complex with a membrane-bound nucleus and many membrane-bound organelles in the cytoplasm
    • The primary difference is presence of a membrane-bound nucleus or nucleoid.

    Microbial Evolution and Diversity

    • Procaryotes (bacteria and archaea) are older than eucaryotes
    • Microbes have existed for billions of years on Earth
    • Microbes have adapted to a wide range of environments
    • Microbes play important roles in various ecosystems, including as decomposers, producers, and symbionts with other organisms

    Prions and Viruses

    • Prions are protein molecules lacking nucleic acid, and cause infectious disease in mammals
    • Viruses are non-cellular agents consisting of genetic material (either DNA or RNA) surrounded by a protein coat and are dependent on a host cell to replicate
    • Viruses are not considered complete living things because they cannot reproduce without a host cell.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    MB Unit 1 PDF

    More Like This

    Untitled Quiz
    6 questions

    Untitled Quiz

    AdoredHealing avatar
    AdoredHealing
    Untitled Quiz
    37 questions

    Untitled Quiz

    WellReceivedSquirrel7948 avatar
    WellReceivedSquirrel7948
    Untitled Quiz
    55 questions

    Untitled Quiz

    StatuesquePrimrose avatar
    StatuesquePrimrose
    Untitled Quiz
    48 questions

    Untitled Quiz

    StraightforwardStatueOfLiberty avatar
    StraightforwardStatueOfLiberty
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser