Post on 18-Dec-2015
TaxonomyThe modern science of taxonomy began in
the mid 18th cent.founded by Carolus Linnaeus
Taxonomy: Identifying, naming and classifying of organisms.
Systematics: Science dealing with the relationship of organisms to one another.
Phylogeny: The evolutionary history of an organism and its relationship to other species.
Phylogenetic tree
Cladistics Phylogenetic tree is constructed using traits
that have been inherited from a common ancestor.
Organisms related by descent are called a clade.Derived characters: Jaws
LungsAmniotic membraneHairNo tailBipedal
Phylogenetic Tree from Cladistics Sequence of branching implies order that new traits evolved Most likely hypothesis based on existing evidence
Traditional TaxonomyDomain (Super kingdom)KingdomPhylumClassOrderFamilyGenusSpecies
Kings Play Chess On Fat Guys Stomachs
Binomial SystemLinnaeus proposed a two name Latin system
for classification.Genus: A group of very similar organisms
related by common descent from a recent ancestor and sharing similar physical traits.
Species: A specific kind of organism in a genus. A group within a genus that share the same set of structural traits and can successfully interbreed with one another.
Genus and species are italicized with genus capitalized.
Canis familiaris
Domain: EukaryotaKingdom: AnimaliaPhylum:ChordataClass: MammaliaOrder: CarnivoraFamily: CanidaeGenus: CanisSpecies: familiarisCommon name: Dog
Pandinus imperator
Classifying organisms:Linnaeus: 2 kingdom- Plantae and Animalia
Whittaker: 5 kingdom- Monera, Protista, Fungi, Plantae and Animalia
Woese: 6 kingdom- Bacteria, Archaea, Protista, Fungi, Plantae and Animalia
Woese (1996): 3 domain- Bacteria, Archaea and Eukarya
Chapter 16
Organismal DomainsProkaryotes Eukaryotes1-5 um in size10X’s more biomassWider range of
environmentsGreater diversitySingle, circular
chromosomeBest known as bacteria
Disease causing agents are pathogens
Can live without the other
10-100 um in sizeMembrane bound
nucleus and organellesDNA arranged on
multiple chromosomesCan’t live without
prokaryotes
Prokaryotic ShapeCocci
Spherical and occur in chains or clusters
E.g. streptococcus and staphylococci
BacilliRod shaped and occur
singularly, in pairs, or chains
E.g. soil organismsVarious shapes
Vibrios resemble commasSpirilla are short, rigid
helical shapesSpirochetes are longer,
more flexible
Prokaryote External StructureCell wall
Bacteria can be gram (+) or gram (-) (+) simple walls with thicker peptidoglycan (sugar
polymer) (-) more complex walls with less peptidoglycan
Lipids and carbs too that make them more threatening, toxic, and resistant to antibiotics
CapsuleSticky polysaccharides or proteins to adhere to
substratesPili
Hairlike appendages for adhesion
Prokaryote Structure
Prokaryotic StructureMotility
Flagella Naked protein structure w/o microtubules that moves in a
propeller-like motionReproduction and adaptation
Divide by binary fission Speed varies from hours to minutes Limited by nutrients, competition, predation, and waste build up
Internal OrganizationSmall genetic rings that aid in resistance called plasmidsSmaller ribosomesWide range of methods to obtain nutrients
Prokaryotic NourishmentBiofilms
Surface coating colonies of prokaryotes
Can be 1 or more species
E.g. dental plaque, UTI’s, or sewer treatment
ArchaeaLive where other organisms can’t surviveExtreme halophiles
Salt environmentsE.g Great Salt Lake, Dead Sea, or sewater evaporating
pondsExtreme thermophiles
Very hot waterE.g ocean vents, or acidic conditions
MethanogensAnaerobic environments with methane as a waste
productE.g. swamps and GI tracts of animals
Bacterial Types9 groups
Proteobacteria Gram negative
Gram positiveChlamydiasSpirochetesCyanobacteria
ProteobacteriaAlpha (α)
Live in root nodules to fix atmospheric nitrogenForeign DNA carriers into crop plant genomes
Gamma (γ)PhotosyntheticInhabit animal intestines
E.g Salmonella, Vibrio cholerae, and Escheria coliDelta (δ)
Slime secreting myxobacteriaCan form fruiting bodies for selves when food is
scarceAttacks other bacteria
ActinomycetesGram Positive BacteriaForm colonies of branched chains of cells or are
solitaryFound in the soil
Streptomycin cultured by pharmaceutical companies,
Bacillus anthracis Form endospores, cell within a cell that dehydrates and
lies dormant till more favorable conditions existStaphylococcus and streptococcusMycoplasmas
Lack cell walls Tiniest of all known cells
Other Bacterial PhylaChlamydias
Live inside eukaryotesCommon cause of blindness (developing
countries) and most common STD (United States)Spirochetes
Spiral through environments by rotating internal filaments
E.g Treponema pallidum (syphilis) and Borrelia burgdorferi (Lyme disease)
CyanobacteriaOxygen-generating photosynthesis (only bacteria)Food for freshwater and marine ecosystems
Bacterial PoisonsExotoxins are proteins secreted by bacteria
Can exist in the bacteria Clostridium tetani produces muscle spasms (lockjaw) Staphylococcus aureus common on skin and in nasal passages
Produces several types causing varying problemsAcquired from genetic transfer between species
E. coli benign resident of intestines Acquires genes that produce harmful effects
Endotoxins are components of gram (-) outer membranesReleased when cell dies or digested by defensive cellCause same general symptoms
Neisseria meningitidis (bacterial meningitis) and Salmonella (typhoid fever)
Disease ControlImprovements in sanitation
Water treatment and sewer systemsAntibiotic development
Increase in bacterial resistanceEducation
Importance of seeking treatmentPrevention
Biological weapons
Biological WeaponsInhalation anthrax (Bacillus anthracis)
Manufacture endospores to disperse into air Once in lungs they multiply and produce exotoxins
Antibiotics kill the bacteria but can’t eradicate from body
Pnemonic plague (Y. pestis)Airborne as lung tissue is coughed up
Botulinum exotoxin (C. botulinum)Deadliest poison on earthBlocks transmission of nerve signals for muscle
contractionLimited availability of antitoxin
BioremediationUse of organisms to remove pollutantsProkaryotic decomposers major force in sewage
treatmentSolid sludge from filters added to anaerobe
colonies Transformed into use for fertilizer or landfill
Liquid waste over biofilms remove organic material Released into bodies of water
Oil spill and mining site clean up
ProtistsStructure
Membrane bound nucleus with chromosomesOther organelles characteristic of eukaryotesFlagella and cilia in a 9+2 microtubule arrangementUnicellular (most)
Most found anywhere there’s waterSeveral arose from secondary endosymbiosis
Symbiosis is a close association between 2 or more species
Endosymbiont is a species that lives within another species
DiplomonadsHeterotrophicPossibly most ancient lineageNo DNA or electron transport chainAnaerobicE.g Giardia intestinalis
Parasite which derives nutrition from living hosts that are injured by it
Waterbourne parasite often ingested from fecal contaminated water
Parabasalids
HeterotrophicSome energy anaerobicallyE.g Trichomonas vaginalisTravels through reproductive tract
Males and females can be affected, but male symptoms less common
Metronidazole only treatment currentlyResistance is increasing
EuglenozoansCrystalline rod inside the flagellaCan be heterotrophs, photoautotrophs, and
pathogenic parasitesE.g Trypanosoma
Causes sleeping sicknessSpread by African tsetse fly
E.g EuglenaCommon in pond water
AlveolatesMembrane-enclosed sacs below the plasma
membraneStabilize cell surface or regulate and ion content
DinoflagellatesMarine and fresh phytoplanktonRed tide blooms, toxins kill fish and can affect humans
Ciliates2 types of nuclei, 1 for daily activities and 1 for
reproduction E.g Paramecium or Stentor
ApicomplexansParasites of animals
E.g Plasmodium which causes malaria
AmoebozoansMove and feed by lobe shaped
pseudopodia, temporaryextensions of the cell
Parasitic amoebasCause dysentery
Slime moldsOrganisms found in moist, decaying matterSpread under favorable conditions, form spore
producing structures under less favorable ones Plasmodium, single multinucleated mass of cytoplasm Cellular slime molds, solitary until food is scarce
Foraminiferans and RadiolariansMove and feed by thread like psuedopodiaForams
Marine and fresh water organismsHave porous shells of CaCO3 called tests
Psudopodia extend through
RadiolariansMarineInternal shell of silica and outer test
StramenopilesMultiple ‘hairy’ flagella and a single ‘smooth’
flagellumWater molds
Decompose dead plants and animalsCan be parasitic (Ireland potato famine)
DiatomsGlassy cell wall of silicaFresh and marine organisms
Brown algaeAutotrophicCommonly called seaweed