Microbial Diversity Session 1: Bacterial Nomenclature
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Questions and Answers

What factor largely determines whether bacteria are pathogenic?

  • The size of the bacterial colony
  • The age of the bacteria
  • The environment in which the bacteria are found (correct)
  • The temperature they are exposed to

    • Which of the following describes pleomorphic bacteria?

  • Bacteria that are only capable of aerobic respiration
  • Bacteria that exhibit uniform size and structure
  • Bacteria that remain the same shape under all conditions
  • Bacteria that can change shape depending on environmental conditions (correct)

    • Which method is used to classify bacteria based on their cell wall composition?

  • Gram staining (correct)
  • Genetic sequencing
  • Metabolic classification
  • Morphological classification

    • What do bacteria that can metabolize lactose indicate about their metabolic activity?

    <p>They possess specific enzymes for lactose breakdown (A)</p> Signup and view all the answers

    Which term refers to the classification of bacteria based on their observable characteristics?

    <p>Phenotypic classification (B)</p> Signup and view all the answers

    What is the role of the mosquito in the life cycle of Plasmodium?

    <p>It acts as both a host and a vector. (C)</p> Signup and view all the answers

    Which of the following is NOT a habitat where parasites can reside?

    <p>Atmosphere (A)</p> Signup and view all the answers

    From which of the following sources can parasitic infections NOT commonly originate?

    <p>Sunlight (D)</p> Signup and view all the answers

    What are endoparasites known for?

    <p>Living within the host and causing infection (A)</p> Signup and view all the answers

    How can cats contribute to the transmission of toxoplasmosis?

    <p>By excreting the parasite in their feces. (B)</p> Signup and view all the answers

    Why is it important for pregnant individuals to avoid contact with litter trays?

    <p>It may result in exposure to parasites that cause miscarriages. (D)</p> Signup and view all the answers

    Which of the following types of hosts is characterized as carrying a parasite but not necessarily showing symptoms of disease?

    <p>Reservoir host (D)</p> Signup and view all the answers

    What is a key feature that differentiates permanent parasites from temporary parasites?

    <p>They are always fixed to the host (C)</p> Signup and view all the answers

    In which type of host does the adult or sexually reproducing form of the parasite primarily live?

    <p>Definitive host (B)</p> Signup and view all the answers

    Opportunistic parasites are most likely to cause diseases in which type of hosts?

    <p>Immunodeficient hosts (D)</p> Signup and view all the answers

    What factor can result in some genes being absent in certain organisms due to their evolutionary history?

    <p>Gene loss (A)</p> Signup and view all the answers

    What mechanism allows unrelated bacteria to acquire resistance genes from others?

    <p>Horizontal gene transfer (C)</p> Signup and view all the answers

    How do Gram-positive bacteria generally develop resistance to Penicillin?

    <p>By producing a binding protein that ignores the antibiotic (D)</p> Signup and view all the answers

    Which of the following is NOT a component of functional diversity in microorganisms?

    <p>Genetic (A)</p> Signup and view all the answers

    What is a key reason why function and phylogenetic correlation may not always align?

    <p>Convergent evolution (D)</p> Signup and view all the answers

    What type of testing can be used to assess the metabolic activities of microorganisms?

    <p>Biochemical testing (D)</p> Signup and view all the answers

    How do Gram-negative bacteria primarily resist Penicillin?

    <p>By employing an enzyme to break it down (C)</p> Signup and view all the answers

    What type of environment can microorganisms inhabit?

    <p>Any conceivable habitat (C)</p> Signup and view all the answers

    How do fungi primarily grow and spread?

    <p>By forming a mycelial network (D)</p> Signup and view all the answers

    What is a method of asexual reproduction in yeast?

    <p>Budding (C)</p> Signup and view all the answers

    What enables mycelium to develop and disperse spores?

    <p>Mitosis (C)</p> Signup and view all the answers

    Which process introduces genetic variation in fungi?

    <p>Meiosis (D)</p> Signup and view all the answers

    Which factor is NOT mentioned as a potential driver for dimorphism in Ascomycetes?

    <p>Changes in humidity (D)</p> Signup and view all the answers

    What happens during sporulation?

    <p>Spores disperse and grow (A)</p> Signup and view all the answers

    In sexual reproduction of yeast, how many haploid ascospores are formed after meiosis?

    <p>4 (D)</p> Signup and view all the answers

    What best characterizes the spores produced by fungi?

    <p>Sizes and shapes (B)</p> Signup and view all the answers

    What can result from the feeding habits of a parasite?

    <p>Nutrient deficiency in the host (D)</p> Signup and view all the answers

    Which of the following statements about direct life cycles of parasites is true?

    <p>They involve a single definitive host. (C)</p> Signup and view all the answers

    What differentiates protozoa from metazoa in terms of classification?

    <p>Protozoa are unicellular, while metazoa are multicellular. (C)</p> Signup and view all the answers

    Which of the following is an example of a nematode?

    <p>Haemonchus contortus (D)</p> Signup and view all the answers

    What role do ticks play in relation to zoonotic diseases?

    <p>They serve as vectors for diseases like Lyme disease. (B)</p> Signup and view all the answers

    What is a common characteristic of arthropods?

    <p>They possess an external skeleton. (B)</p> Signup and view all the answers

    Which organism is classified as a systemic protozoan parasite?

    <p>Plasmodium falciparum (C)</p> Signup and view all the answers

    What is a defining feature of helminths?

    <p>They are multicellular organisms. (A)</p> Signup and view all the answers

    Which disease is caused by the protozoan Trypanosoma brucei?

    <p>Sleeping sickness (A)</p> Signup and view all the answers

    How do nematodes typically enter a new host?

    <p>They are ingested through contaminated water. (C)</p> Signup and view all the answers

    What is swine flu scientifically known as?

    <p>H1N1 (A)</p> Signup and view all the answers

    What type of parasite are fleas classified as?

    <p>Arthropods (D)</p> Signup and view all the answers

    What is a significant impact of viruses on human social behavior?

    <p>Changes in travel behavior and health precautions. (B)</p> Signup and view all the answers

    What is the primary concern regarding the governmental response to swine flu in Egypt?

    <p>Killing all pigs despite them not being the source. (D)</p> Signup and view all the answers

    Study Notes

    • Microbial diversity, bacteria, session 1, 2/12/2024

    Bacterial Nomenclature

    • Bacteria can be beneficial or harmful; environment is critical
    • Bacteria have relationships with their environment
    • Bacteria can be classified as pathogenic or not

    Bacterial Taxonomy/Nomenclature

    • Bacterial names have different origins
    • Scientists, places, colors
    • Staphylococcus aureus = grape-like clusters under microscope
    • Numerous ways to classify bacteria

    Phenotypic Classifications

    • Cell morphology – appearance under microscope, movement
    • Pleiomorphic bacteria – change shape based on environment
    • Metabolic activity – respiration, lactose metabolism or alternative sources
    • Staining – distinguishing by cell wall or membrane, Gram staining
    • Pathogenicity – antibiotic and heavy metal resistance, toxins, harm

    Nutritional needs

    • DNA based
    • G-C content

    16S rRNA sequencing

    • Used to classify archaea and bacteria, useful to understand diversity
    • 16s has regions that vary depending on species or organism

    18s RNA sequencing

    • Used to classify eukaryotic species (or organisms)

    Metagenomics

    • Sequencing of the whole sample, looking at overall genetic variation
    • No need for culture, identifying organisms without isolating

    Functional Diversity

    • Physiological functions – metabolism, biochemistry, and processes
    • Morphology – appearance on plates, under microscope, staining
    • Ecological role, interaction with other microbial species, environment

    Microbial Habitats

    • Microbes are found everywhere
    • Thermophiles – thrive in high temperatures
    • Psychrophiles – thrive in low temperatures
    • Halophiles – thrive in high-salt environments

    Diversity of Bacteria

    • 55 bacterial phyla
    • Many more are in Candidatus status

    Bacteria Phyla

    • Proteobacteria
    • Alpha, beta, gamma, delta, epsilon, and zeta proteobacteria
    • Six classes
    • 1 Alphaproteobacteria
    • Many are anaerobic, prefer low-nutrition
    • 2 Betaproteobacteria
    • Can be nitrogen fixers
    • 3 Gammaproteobacteria

    Classification of Bacteria

    • Shape
    • Growth needs (oxygen demand)
    • pH
    • Mode of nutrition
    • Osmotic pressure
    • Temperature
    • Number of flagella
    • Spore formation
    • Others

    Bacterial Phyla – Specific Examples

    • Thermophilic phyla (e.g., Aquificae/Aquificota)
    • Have a flagella that enables motility
    • Don't have endospores
    • Most are chemolithoautotrophs – produce energy from chemical sources
    • Deinococcota
    • Very thick cell wall, two membranes
    • Heterotrophic
    • Strictly aerobic
    • Can resist ionizing and UV radiation

    Chloroflexi/ Chloroflexota

    • Tend to be green due to proteins/chemicals inside
    • Lack an outer membrane
    • Generally, do not stain Gram positive but mostly negative
    • Found in moderate thermophiles (around 80 degrees Celcius)
    • Long and filamentous morphology

    Cyanobacteria

    • Photosynthetic species
    • Often green from chlorophyll
    • Chlorophyll is present in carboxysomes – CO2 fixation occurs there
    • Responsible for free oxygen in the atmosphere
    • Found in aquatic and land environments

    Spirochaetota

    • Spiral/helical shape
    • Almost all are Gram-negative
    • Majority are anaerobes or facultative anaerobes
    • Flagella helps them swim, which are called endo flagella
    • Treponema pallidum – syphilis, Borrelia burgdorferi – Lyme disease

    Chlamydiota

    • Intracellular parasites
    • Require a host cell to reproduce
    • Stain gram negative
    • Unique life cycles, (elementary bodies, inclusion bodies)

    Firmicutes

    • Gram-positive, very low GC content
    • Includes cocci bacteria
    • Many are facultative anaerobes
    • Some produce endospores for survival
    • Examples: bacteria used for cheese production

    Bacteriodetes

    • Gram-negative
    • Many can break down complex polysaccharides
    • Are mostly obligate anaerobes
    • Found in animal intestines, but are generally commensal

    Diversity of Archaea

    • Very recent research
    • Many are identified and characterized by more research

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    Microbial Diversity: Bacteria, Session 1 PDF

    Description

    Explore the fascinating world of bacteria in this quiz focused on bacterial nomenclature and taxonomy. Understand the various classifications of bacteria based on their morphology, metabolism, and pathogenicity. Dive into the significance of 16S rRNA sequencing in unraveling microbial diversity.

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