diversity of living things

• Characteristics of living things

  • Made up of cells
  • Sense change in environment
  • Movement
  • Reproduce
  • Grow
  • Respire
  • Produce waste
  • Limited lifespan
• Scientific naming


  • Genus (first letter capital)
  • Species (lower case)
  • Italics or underlined
  • Latin
• Phylogenetic trees

  • Clade: single ancestor and all descendants
  • Root: on ancestor to branches
  • Branch: represent shared histories
  • Node: where group split
  • Tips: descendants
• Domains of prokaryotes


  • Bacteria
  • Archaea
• Prokaryotic cells have no membrane bound organelles or nucleus
• Components of prokaryotic cells

  • Cell membrane, pilus, cytoplasm
  • Plasmid
  • Flagella
  • DNA
  • Ribosomes
  • Nucleoid
• Ribosomes


  Create protein
• Capsule


  • Layer of sticky material outside the cell wall
  • Allows cells to cling to surfaces
  • Protects cells from drying out
  • Protects against viruses and antibiotics
• Cell wall


  • Protective layer that gives structure, Made of peptidoglycan (bacteria)
  • Archaea sometimes don't have cell wall
• Plasma membranes


  Allows some substances through
• Plasmids


  • Contain fewer genes but code for enzymes to break down antibiotics
• Flagella


  • Tail-like structure that allows movement
• Pili


  • Hair-like structure that allows cells to stick to surfaces and obtain food
• Nucleoid region


  • Where DNA is coiled up in cytoplasm
• Characteristics of Archaea


  • Extreme conditions
  • Binary fission
  • No peptidoglycan
  • Always heterotrophs
• Characteristics of Bacteria


  • Live everywhere
  • Prokaryotes
  • Binary fission
  • Cell wall has peptidoglycan
  • Autotroph (cyanobacteria) or heterotroph (decomposer)
• How information on environment helps control bacterial growth

  Knowing the ideal environment allows providing unfavourable conditions like lack of food, water, or temperature
• Biological roles of Bacteria

  • Helpful: Plant growth, food digestion, food production, decomposition
  • Harmful: E.Coli, tooth decay, Salmonella
• Binary fission


  1. Asexual - forms two identical cells

  2. Exponential growth - repeated doubling

  3. Doubling time measures population growth, parent cells grow larger and DNA is copied, cell splits into 2 identical daughter cells
• Bacterial horizontal gene transfer

  • Conjugation
  • Transformation
  • Transduction
• Bacterial cell wall characteristics

  • Purple bacteria - thick peptidoglycan layer, easier to treat
  • Pink bacteria - thin peptidoglycan layer, harder to treat
• Antibiotic testing


  1. Sample placed on agar with ideal growth environment

  2. Antibiotics placed on agar kill bacteria

  3. Zone of inhibition shows most effective antibiotic
• Bacteria can evolve resistance to antibiotics when used improperly or excessively
• Overuse of antibiotics can lead to the development of superbugs - drug-resistant bacteria. the bacteria cells evolve and get a defence mechanism against antibiotics and become stronger and stronger
• Viruses


  • Non-living
  • Not made of cells
  • Don't grow
  • Can't make their own energy
  • Can't maintain a stable state
• Virus structure


  • Internal: RNA or DNA
  • Surrounded by protein capsid
  • Some have membrane envelope
• Virus classification


  • Double-stranded
  • Genetic material: RNA or DNA
  • Shape: spherical, complex, polyhedral, helical
• Virus replication


  • Lysogenic (long) - DNA incorporates with host cell DNA (provirus), can replicate for a long time, some conditions DNA activates and selerates from host DNA lyric cycle starts
  • Lytic cycle - host cell makes virus, cell bursts, infects other cells
• Viruses are transmitted by being breathed in or through contact with infectious particles
• Prokaryotes evolved to become eukaryotes through a process of infolding of the cell membrane to create internal membrane-bound organelles
• Mitochondria and chloroplasts were once prokaryotic organisms, they have their own DNA and double stranded membrane
• Eukaryotic (domain) kingdoms

  • Plants, fungi, protista, animalia
• Protists characteristics

  • Eukaryotic, most single-celled, aquatic, three categories of nutrition (plant-like, fungi-like, animal-like), asexual and sexual
• Animal-like protists


  • Heterotrophs, protozoa, motile, no cell wall, some parasitic
• Fungus-like protists


  • Heterotrophs, absorb nutrients from other organisms, some glide to find nutrients
• Plant-like protists


  • Autotrophs, chloroplasts, some consume organisms or move to find light, cell wall of cellulose
• Protists biological role is: decomposers, produce oxygen, some diseases caused by protists
• Climate change can disrupt ocean acidity, temperature, and nutrient availability in ecosystems for protists
• Fungi


  • Eukaryotic, cell wall of chitin or cellulose, reproduce sexually with spores and asexually with slitting , heterotrophs, external digestion, their structure is with many nuclei, most multicellular (yeast) and have hyphae (a network of fine filaments)
• Fungal reproduction


  Drop spores - grow into hyphae - combine - grow mycelium - pinhead - into mushroom