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The Microbial World and You
Microorganisms
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How are microbes named and classified?
 Linnaeus established
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 Each organism has two names:
 __________________________________________________________________
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 Are “Latinized” and used worldwide.
 May be descriptive or honor a scientist.
Scientific Names
 Staphylococcus aureus
 Describes the clustered arrangement of the cells (staphylo-) and the golden color
of the colonies
(aur-).
 Escherichia coli
 Honors the discoverer, Theodor Escherich, and describes the bacterium’s habitat–
the large intestine or colon
Taxonomy
What is systematics?
 Study of phylogenetic relationships
 Phylogenetics =
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 Taxonomy =
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 Also a way of organizing/ classifying
 Taxa (taxon—singular)
How are prokaryotes classified?
 Divides prokaryotes into (based on rRNA sequences)
 __________________________
 __________________________
Who is Carl Woese?
 1978: created current classification scheme
 Three domains
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 Eukarya
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What is the taxonomy of organisms?
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How are eukaryotes classified?
 Endosymbiotic theory
 Numerous kingdoms, including
 Protista
 Fungi
 Plantae
 Animalia
What about viruses—How are they classified?
 Not included in three domains, which are ____________ ___________ and ______
 Why not?
 Viral species: population of viruses with similar characteristics
A closer look at the microbes
What are bacteria?
 Simple, single-celled
 Prokaryotes
 ______________________________________________________________
 Come in different shapes
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 Peptidoglycan cell wall
 Binary fission
 Some have flagella
What are archaea?
 Also prokaryotes
 ________________________________________________________________________
 Live in extreme conditions
 __________________________________________________________________
 Hyperthermophiles
 Methanogens
 ________________________________________________________________________
What are fungi?
 Eukaryotes
 Have a true nucleus
 ________________________________________________________________________
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 Includes
 Molds
 Mushrooms
 Yeasts
 Slime molds
 Sexual and asexual reproduction
What are protozoa?
 Eukaryotes
 ________________________________________________________________________
 May be motile via pseudopods, cilia,
or flagella
What are algae?
 Eukaryotes
 Cellulose cell walls
 ________________________________________________________________________
 Produce molecular oxygen and organic compounds
What are viruses?
 ________________________________________________________________________
 ________________________________________________________________________
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 Coat may be enclosed in a lipid envelope.
 Viruses are replicated only when they are in a living host cell.
What are multicellular animal parasites?
 Eukaryote
 ________________________________________________________________________
 Parasitic flatworms and round worms are called ________________________________.
 Microscopic stages in life cycles.
What are infectious diseases?
 When a pathogen overcomes the host’s resistance, disease results.
 Emerging infectious diseases (EID): ___________________________________________.
 West Nile Virus
 Bovine spongiform encephalopathy
 Ebola hemorrhagic fever
 Hantavirus
 AIDS
 Anthrax