Podcast
Questions and Answers
What process allows the transfer of DNA between bacterial cells through a bridge?
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?
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?
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?
What is one of the primary causes of bacterial resistance to antibiotics?
Which method is NOT effective for food preservation against bacterial growth?
Which method is NOT effective for food preservation against bacterial growth?
Which of the following statements is true concerning Gram-negative bacteria?
Which of the following statements is true concerning Gram-negative bacteria?
What are the shapes of bacteria classified as bacilli?
What are the shapes of bacteria classified as bacilli?
How do extreme thermohalophiles typically thrive?
How do extreme thermohalophiles typically thrive?
What is the primary method through which bacteria reproduce asexually?
What is the primary method through which bacteria reproduce asexually?
Which grouping characterizes bacteria that form chains?
Which grouping characterizes bacteria that form chains?
What is a distinguishing characteristic of Gram-positive bacteria?
What is a distinguishing characteristic of Gram-positive bacteria?
What is the process through which plasmids are exchanged between bacteria?
What is the process through which plasmids are exchanged between bacteria?
Which type of mobility mechanism do some bacteria use to move through environments?
Which type of mobility mechanism do some bacteria use to move through environments?
Which kingdom is known for having a cell wall that lacks peptidoglycan?
Which kingdom is known for having a cell wall that lacks peptidoglycan?
In which kingdom do most organisms absorb their food from the environment?
In which kingdom do most organisms absorb their food from the environment?
What type of organisms can be found in the Kingdom Protista?
What type of organisms can be found in the Kingdom Protista?
Which kingdom includes organisms that reproduce both sexually and asexually?
Which kingdom includes organisms that reproduce both sexually and asexually?
Which of the following characteristics distinguishes Kingdom Animalia from other kingdoms?
Which of the following characteristics distinguishes Kingdom Animalia from other kingdoms?
Which of the following kingdoms contains both unicellular and multicellular organisms?
Which of the following kingdoms contains both unicellular and multicellular organisms?
Which statement is true about Kingdom Eubacteria?
Which statement is true about Kingdom Eubacteria?
What is a common habitat for organisms in the Kingdom Archaebacteria?
What is a common habitat for organisms in the Kingdom Archaebacteria?
What is the primary purpose of taxonomy in biology?
What is the primary purpose of taxonomy in biology?
Which part of the scientific name identifies the genus to which an organism belongs?
Which part of the scientific name identifies the genus to which an organism belongs?
What is the correct way to write the scientific name of an organism?
What is the correct way to write the scientific name of an organism?
Which of the following statements regarding taxonomic categories is true?
Which of the following statements regarding taxonomic categories is true?
Which scientist is credited with developing the binomial nomenclature system?
Which scientist is credited with developing the binomial nomenclature system?
Why was the Kingdom Monera split into two different taxa?
Why was the Kingdom Monera split into two different taxa?
What does molecular analysis in taxonomy primarily focus on?
What does molecular analysis in taxonomy primarily focus on?
How does the new domain system categorize organisms?
How does the new domain system categorize organisms?
Which of the following is NOT a taxonomic category in the hierarchy?
Which of the following is NOT a taxonomic category in the hierarchy?
Which organism’s scientific name is correctly matched with its common name?
Which organism’s scientific name is correctly matched with its common name?
What is the primary function of a dichotomous key?
What is the primary function of a dichotomous key?
Which structure is NOT part of the general structure shared by both domains of bacteria?
Which structure is NOT part of the general structure shared by both domains of bacteria?
What type of Archaebacteria are methanogens, and where can they be commonly found?
What type of Archaebacteria are methanogens, and where can they be commonly found?
Which of the following characteristics describes thermophiles?
Which of the following characteristics describes thermophiles?
Which statement about halophiles is true?
Which statement about halophiles is true?
What does the term 'plasmid' refer to in bacteria?
What does the term 'plasmid' refer to in bacteria?
Which observable trait might lead to identifying an organism as belonging to the BB classification in a dichotomous key?
Which observable trait might lead to identifying an organism as belonging to the BB classification in a dichotomous key?
Which is a key characteristic of the capsule surrounding some bacterial cells?
Which is a key characteristic of the capsule surrounding some bacterial cells?
Flashcards are hidden until you start studying
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
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
