Prokaryotes, Fungi, Protists and Viruses

• What are the two main types of prokaryotic cells?

  Archaea and Bacteria
• What are the main components of prokaryotic cells?

  • Cytoplasm
  • Cell wall
  • Ribosomes
  • Storage granules
  • Metabolic enzymes
• What is the function of the prokaryotic cell wall?

  Support and maintain cell shape
• What is peptidoglycan?

  A complex polymer in Eubacteria cell walls
• How do prokaryotes move in their environment?

  Most use flagella for motility
• What powers the flagellar motor in prokaryotes?

  Energy from ATP and proton diffusion
• What is the primary method of reproduction in prokaryotes?

  Binary fission
• What happens during binary fission in prokaryotes?

  Circular DNA replicates and divides
• What is a plasmid?

  A small ring of DNA in bacteria
• How do prokaryotes exchange genetic material?

  Through transformation, transduction, and conjugation
• What are the three methods of genetic exchange in Eubacteria?

  1. Transformation: uptake of DNA fragments
  2. Transduction: gene transfer via phages
  3. Conjugation: direct transfer between cells
• What are the three domains of life?

  Bacteria, Archaea, and Eukarya
• What is a characteristic of Eubacteria?

  They have peptidoglycan in their cell walls
• What distinguishes Archaea from Bacteria?

  They are molecularly distinct from bacteria
• What are methanogens?

  Methane-producing Archaea
• Where do methanogens typically live?

  In oxygen-free environments
• What do halophiles require for survival?

  High salt concentrations
• What is bacteriorhodopsin?

  A pigment used in photosynthesis by halophiles
• What environments do thermophiles thrive in?

  Hot and sometimes acidic environments
• What is the structure of bacterial cells primarily composed of?

  Peptidoglycan and plasma membrane
• What is the function of the bacterial capsule?

  Protects and helps bacteria adhere
• What is the role of mesosomes in bacterial cells?

  Their role is unclear and debated
• What do plasmids code for in bacteria?

  Traits like antibiotic resistance
• What is the function of pili in bacteria?

  To attach bacteria to surfaces
• How are bacteria classified?

  • Scientific name (Genus species)
  • Staining of cell wall
  • Shape
  • Oxygen requirements
  • Mode of nutrition
• What does the Gram stain indicate about bacteria?

  It shows the thickness of peptidoglycan walls
• What color do Gram-positive bacteria stain?

  Violet
• What color do Gram-negative bacteria stain?

  Red
• What is the significance of bacterial morphology?

  It helps in identifying bacterial species
• What are the three shapes of bacteria?

  Cocci, bacilli, and spirilla
• What are obligate aerobes?

  Bacteria that need oxygen to survive
• What are facultative bacteria?

  Bacteria that can grow with or without oxygen
• What are the characteristics of fungi?

  • Eukaryotic with a membrane-enclosed nucleus
  • Heterotrophs that decompose organic material
  • Cell wall made of chitin
  • Reproduce by spores
• What is the cell wall of fungi made of?

  Chitin
• What are the two types of fungal body plans?

  Mould and yeast
• What is mycelium?

  The main body of multicellular fungi
• What is the role of yeasts in baking?

  They produce CO₂ for leavening
• What are the symbiotic relationships involving fungi?

  • Lichens: fungi and photosynthetic algae
  • Mycorrhiza: fungi with plant roots
  • Ruminant gut: fungi aiding cellulose breakdown
• What are the problems caused by fungi?

  Mycotoxins and diseases in plants and animals
• What is the importance of fungi in ecosystems?

  They are decomposers and nutrient recyclers