Taxonomy Fundamentals
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Questions and Answers

What process allows the transfer of DNA between bacterial cells through a bridge?

  • Binary fission
  • Transformation
  • Transduction
  • Conjugation (correct)
  • What is the role of endospores in bacteria?

  • To enhance nutrient absorption
  • To increase motility
  • To protect DNA in unfavorable conditions (correct)
  • To facilitate reproduction
  • Which human use of bacteria does NOT contribute to environmental management?

  • Cleaning up oil spills
  • Food production (correct)
  • Sewage treatment
  • Production of vitamins in intestines
  • What is one of the primary causes of bacterial resistance to antibiotics?

    <p>Overuse or misuse of antibiotics</p> Signup and view all the answers

    Which method is NOT effective for food preservation against bacterial growth?

    <p>Allowing food to sit at room temperature</p> Signup and view all the answers

    Which of the following statements is true concerning Gram-negative bacteria?

    <p>They have a complex cell wall structure with three layers.</p> Signup and view all the answers

    What are the shapes of bacteria classified as bacilli?

    <p>Rod shaped</p> Signup and view all the answers

    How do extreme thermohalophiles typically thrive?

    <p>In high-temperature environments such as hot springs</p> Signup and view all the answers

    What is the primary method through which bacteria reproduce asexually?

    <p>Binary fission</p> Signup and view all the answers

    Which grouping characterizes bacteria that form chains?

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

    What is a distinguishing characteristic of Gram-positive bacteria?

    <p>They retain the crystal violet stain and appear purple.</p> Signup and view all the answers

    What is the process through which plasmids are exchanged between bacteria?

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

    Which type of mobility mechanism do some bacteria use to move through environments?

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

    Which kingdom is known for having a cell wall that lacks peptidoglycan?

    <p>Kingdom Archaebacteria</p> Signup and view all the answers

    In which kingdom do most organisms absorb their food from the environment?

    <p>Kingdom Fungi</p> Signup and view all the answers

    What type of organisms can be found in the Kingdom Protista?

    <p>Both autotrophic and heterotrophic organisms</p> Signup and view all the answers

    Which kingdom includes organisms that reproduce both sexually and asexually?

    <p>All of the above</p> Signup and view all the answers

    Which of the following characteristics distinguishes Kingdom Animalia from other kingdoms?

    <p>Absence of cell walls</p> Signup and view all the answers

    Which of the following kingdoms contains both unicellular and multicellular organisms?

    <p>Kingdom Protista</p> Signup and view all the answers

    Which statement is true about Kingdom Eubacteria?

    <p>They are found in nearly every environment.</p> Signup and view all the answers

    What is a common habitat for organisms in the Kingdom Archaebacteria?

    <p>Volcanic hot springs</p> Signup and view all the answers

    What is the primary purpose of taxonomy in biology?

    <p>To accurately and uniformly name organisms</p> Signup and view all the answers

    Which part of the scientific name identifies the genus to which an organism belongs?

    <p>The first part of the name</p> Signup and view all the answers

    What is the correct way to write the scientific name of an organism?

    <p>Italicized with the genus capitalized and species in lowercase</p> Signup and view all the answers

    Which of the following statements regarding taxonomic categories is true?

    <p>Linnaeus established a system with eight taxonomic ranks</p> Signup and view all the answers

    Which scientist is credited with developing the binomial nomenclature system?

    <p>Carolus Linnaeus</p> Signup and view all the answers

    Why was the Kingdom Monera split into two different taxa?

    <p>Because of large differences in cellular structure</p> Signup and view all the answers

    What does molecular analysis in taxonomy primarily focus on?

    <p>DNA sequence comparisons among species</p> Signup and view all the answers

    How does the new domain system categorize organisms?

    <p>Into three broad groups reflecting molecular evidence</p> Signup and view all the answers

    Which of the following is NOT a taxonomic category in the hierarchy?

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

    Which organism’s scientific name is correctly matched with its common name?

    <p>Ursus arctos - Grizzly Bear</p> Signup and view all the answers

    What is the primary function of a dichotomous key?

    <p>To identify unfamiliar organisms through observable traits</p> Signup and view all the answers

    Which structure is NOT part of the general structure shared by both domains of bacteria?

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

    What type of Archaebacteria are methanogens, and where can they be commonly found?

    <p>They are chemoautotrophic anaerobes found in swamps and landfills.</p> Signup and view all the answers

    Which of the following characteristics describes thermophiles?

    <p>They can grow at temperatures above boiling point.</p> Signup and view all the answers

    Which statement about halophiles is true?

    <p>They are aerobic organisms living in saline conditions.</p> Signup and view all the answers

    What does the term 'plasmid' refer to in bacteria?

    <p>Circular DNA used for sexual reproduction</p> Signup and view all the answers

    Which observable trait might lead to identifying an organism as belonging to the BB classification in a dichotomous key?

    <p>The organism is round and orange.</p> Signup and view all the answers

    Which is a key characteristic of the capsule surrounding some bacterial cells?

    <p>It protects the bacteria from harsh environmental conditions.</p> Signup and view all the answers

    Study Notes

    Taxonomy

    • The science of classifying organisms
    • Around 1.7 million species identified and named
    • Estimated 8 million more unknown species
    • Aristotle first classified organisms into land, sea, and air dwellers
    • Organisms need a name and organization
    • Uses Latin for consistent naming
    • Each species has only one scientific name
    • Same name not used for different species
    • Shows evolutionary relationships

    Taxonomic Categories & Hierarchy

    • Linnaeus grouped organisms into taxa based on structure and function (morphology)
    • Eight taxa within taxonomy: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
    • Classification is organized from smallest to largest
    • Each level groups organisms with more shared characteristics than the level before

    Binomial Nomenclature

    • Developed by Carl Linnaeus
    • A two-part scientific name for each species
    • First part identifies the genus (group of closely related species)
    • Second part is unique to each species within the genus
    • Scientific names are always written in italics when typed
    • The first letter of the genus is capitalized, and the second word is lowercase
    • Example: Ursus arctos (Grizzly Bear)
    • Can be underlined when handwriting

    Traditional Taxonomy

    • Two Kingdom System (Linnaeus): Animalia and Plantae
    • Five Kingdom System: Monera, Protista, Fungi, Plantae, Animalia
    • Six Kingdom System: Eubacteria and Archaebacteria split from Monera

    Molecular Analysis

    • Similarities on the molecular level indicate common ancestors
    • Used to determine classification and evolutionary relationships
    • Shows how species have evolved
    • DNA sequence comparisons show relatedness: more similar sequences = more recent common ancestry

    New Domain System

    • Reflects understanding of molecular and evolutionary evidence
    • Three domains: Bacteria, Archaea, Eukarya

    3 Domains of Life

    • Bacteria: Peptidoglycan in cell walls, includes bacteria causing disease, unicellular and prokaryotic
    • Archaea: No peptidoglycan in cell walls, live in harsh environments
    • Eukarya: Unicellular and multicellular, eukaryotic, includes Kingdoms Protista, Fungi, Plantae, and Animalia

    Kingdom Archaebacteria

    • “Ancient” bacteria
    • Prokaryotic and unicellular
    • Both autotrophs and heterotrophs
    • Cell wall lacks peptidoglycan
    • Reproduce asexually
    • Some are motile (can move)
    • Live in extreme environments (volcanic hot springs, salt marshes)

    Kingdom Eubacteria

    • “Recent” bacteria
    • Prokaryotic and unicellular
    • Both autotrophic and heterotrophic
    • Reproduce asexually
    • Some are motile
    • Cell wall contains peptidoglycan
    • Live nearly everywhere

    Kingdom Protista

    • Organisms that cannot be classified as animals, plants, or fungi
    • Great variety among members
    • Classified into three groups: Animal-like protists, Plant-like protists, Fungi-like protists
    • Eukaryotic
    • Most are unicellular, some are multicellular
    • Autotrophs and heterotrophs
    • Reproduce sexually and asexually
    • Some are motile
    • Some have a cell wall
    • Live in damp or wet habitats

    Kingdom Fungi

    • Eukaryotic
    • Mostly multicellular, some unicellular (yeast)
    • Heterotrophic: Absorb food from the environment
    • Feed on dead or decaying matter
    • Have a cell wall made of chitin
    • Reproduce sexually and asexually
    • Non-motile
    • Live as parasites or saprophytes

    Kingdom Plantae

    • Eukaryotic and multicellular
    • Photosynthetic, autotrophs
    • Have a cell wall made of cellulose
    • Reproduce sexually and asexually
    • Non-motile
    • Includes cone-bearing and flowering plants, mosses, and ferns

    Kingdom Animalia

    • Eukaryotic and multicellular
    • Heterotrophic
    • Mostly reproduce sexually
    • No cell walls
    • Motile, except sponges
    • Very diverse

    Dichotomous Key

    • A tool for identifying unfamiliar organisms
    • List of observable traits that lead to the organism's name
    • “Dichotomous” means “divided into two parts”
    • Each step has two choices (yes or no)

    General Structure of Bacteria

    • DNA: Dictates cell function, including plasmids for sexual reproduction
    • Ribosomes: Make proteins
    • Cell wall: Provides structure to the bacterial cell
    • Capsule: Thick gelatin around the cell wall, protects bacteria, hardens in harsh conditions
    • Pili: For movement
    • Flagellum: For movement in some bacteria

    Domain Archaea

    • Live in extremely hot, salty, oxygen-poor, toxic environments
    • Oldest known organisms
    • Methanogens, halophiles, and thermophiles are different types of archaea

    Methanogens

    • Chemoautotrophic anaerobes
    • Produce methane as a waste product
    • Found in swamps, sewage, landfills, and guts of large mammals
    • Potential for methane production in sewage treatment and landfills

    Halophiles

    • Salt-loving Archaea
    • Grow in places like salt ponds and lakes
    • Large numbers can turn water a dark pink
    • Aerobic

    Thermophiles

    • Archaebacteria from hot springs and other high-temperature environments
    • Some can grow above the boiling point of water
    • Anaerobic
    • Extreme thermohalophiles grow in high temperatures, like deep-sea hot vents

    Domain Bacteria

    • Found everywhere else
    • Cocci, bacilli, spirilla are different shapes of Eubacteria
    • Diplo-, strepto-, staphylo- groupings describe how bacteria cluster
    • Gram staining helps classify bacteria:
      • Gram-positive: Purple stain, one cell layer, thick peptidoglycan
      • Gram-negative: Pink stain, three cell layers, thin peptidoglycan, thick lipid layer
    • Mobility: Flagella, lashing, gliding, or spiraling movements
    • Reproduction:
      • Binary fission: Asexual, bacterium replicates DNA and divides in half, producing two identical cells
      • Conjugation: Sexual, transfer of plasmids (small, circular DNA) from one bacteria to another
      • Spore formation: In unfavorable conditions, bacteria produce a thick internal wall around DNA and cytoplasm

    Importance of Bacteria

    • Ecological roles: Producers, decomposers, nitrogen fixers
    • Human uses: Foods and beverages, sewage treatment, cleaning up oil spills, synthesis of drugs and chemicals, production of vitamins in the gut
    • Pathogenic bacteria: Cause diseases (pneumonia, tetanus)

    Defending Against Bacterial Infections

    • Prevention: Hand washing, active immunity (vaccination), passive immunity
    • Food preservation: Heat or chemicals to slow down bacterial growth (sterilization, refrigeration, cooking through, canning, freezing, drying)
    • Antibiotics: Compounds that kill or inhibit bacterial growth

    Antibiotic Resistance

    • Bacteria can develop resistance to antibiotics, which is a growing problem

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    Description

    Explore the fascinating world of taxonomy, the science of classifying organisms. Learn about the classification hierarchy, taxonomic categories, and the system of binomial nomenclature developed by Carl Linnaeus. This quiz will help you understand how we organize and name the diverse species of our planet.

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