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Scientific Classification
What’s In a Name??
What are some ways you are
classified?
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gender
age
social security number
income
state/area of residence
profession
Why Classify??
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Human nature- we love to put things in
their place!
Organization
Identification
Less Confusion
Show Relationships
Modern Classification
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Linnaeus
Binomial
nomenclature
Taxon (taxa)
phylogenetics- the
tracing of
evolutionary
relationships
Haeckel (1894)
Three kingdoms
Whittaker (1959)
Five kingdoms
Woese (1977)
Six kingdoms
Woese (1990)
Three domains
Eubacteria
Bacteria
Archaebacteria
Archaea
Monera
Protista
Protista
Protista
Fungi
Fungi
Plantae
Animalia
Eukarya
Plantae
Plantae
Animalia
Animalia
Early history of life
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Solar system~ 12 billion
years ago (bya)
Earth~ 4.5 bya
Life~ 3.5 to 4.0 bya
Prokaryotes~ 3.5 to 2.0
bya stromatolites
Oxygen accumulation~ 2.7
bya photosynthetic
cyanobacteria
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Eukaryotic life~ 2.1 bya
Muticelluar eukaryotes~
1.2 bya
Animal diversity~ 543 mya
Land colonization~ 500
mya
Bacteria
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Kingdom: Monera?
Domain: Bacteria
Domain: Archaea
Prokaryotic- no
membrane-bound
organelles, microscopic
Shape
•cocci (sphere)
•bacilli (rod)
•helical (spiral)
Archaea Vs. Eubacteria
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Domain Archaea
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no membrane- bound
organelles (prok.)
no peptidoglycan
do not respond to
antibiotics
extremophiles
chemoautotrophs,
heterotrophs
3 main groups:
methanogens, extreme
halophiles, extreme
thermophiles
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Domain Eubacteria
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no membrane-bound
organelles (prok.)
peptidoglycan in cell walls
growth inhibited by
antibiotics
diverse metabolism
5 main groups:
spirochetes, chlamydias,
gram+, cyanobacteria,
proteobacteria
Prokaryotes
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Decomposers: unlock organics
from corpses and waste
products
Symbiosis~
•symbiont/host
•mutualism (+, + )
•parasitism (+, -)
•commensalism (+,
0)
Disease
•opportunistic: normal
residents of host; cause illness
when defenses are weakened
•Koch’s postulates: criteria for
bacterial disease confirmation
•exotoxins: bacterial proteins
that can produce disease w/o
the prokaryote present
(botulism)
•endotoxins: components of
gram - membranes
Enter Eukaryotes- Domain Eukarya
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nucleus
membrane-bound
organelles
larger in size than
prokaryotic cells
fungus, plant, and
animal cells
Kingdom Protista (Domain Eukarya)
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Ingestive
(animal-like);
protozoa
Absorptive
(fungus-like)
Photosynthetic
(plant-like);
alga
Kingdom Plantae (Domain Eukarya)
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bryophytes (mosses),
pteridophytes (ferns),
gymnosperms (pines and
conifers); angiosperms (flowering
plants)
Plants: multicellular, eukaryotic,
photosynthetic autotrophs
Terrestrial colonization:
Vascular tissue
The seed
The flower
Gymnosperms (Kingdom Plantae)
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Cone-bearing plants
Lack enclosed chambers
(ovaries) for seeds
Ovules and seeds develop on
specialized leaves called
sporophylls
Ginkgo, cycads, and conifers
All are “evergreens”
Needle-shaped leaves
Vascular tissue refinement:
tracheids~ water conducting
and supportive element of
xylem
Angiosperms (Kingdom Plantae)
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Most diverse and geographically widespread of all plants
“Flowering plants”(Phy: Anthophyta)
Monocots: 1 embryonic seed leaf (lilies, palms, grasses, grain crops)
Dicots: 2 embryonic seed leaves (roses, peas, sunflowers, oaks, maples)
Vascular tissue refinement: vessel elements/fiber cells
Kingdom Fungi (Domain Eukarya)
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Heterotrophic by absorption
(exoenzymes)
Decomposers (saprobes),
parasites, mutualistic
symbionts (lichens)
Hyphae: body filaments
•septate (cross walls)
•coenocytic (no cross walls)
Mycelium: network of
hyphae
Chitin cell walls
(polysaccharide)
Fungi Diversity, I
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Phy: Chytridiomycota
•aquatic fungi; chytrids
•lineage closest to
protists (flagella)
Phy: Zygomycota
•Rhizopus (food mold)
•mycorrhizae:
mutualistic with plant
roots •zygosporangia:
resistant structure
(freezing and drying)
Fungi Diversity, II
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Phy.: Ascomycota
•sac fungi
• yeasts, truffles, morels,
Sordaria
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•asci: sexual spores
•conidia: asexual spores
Phy.: Basidiomycota
• club fungus
•mushrooms, puffballs,
shelf fungus, rusts
•basidiocarps: produce
sexual spores
Kingdom Animalia (Domain
Eukarya)
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heterotrophic
most are mobile
ingestion followed by digestion
multicellular (most have tissues)
lack cell walls
sexual reproduction
35 phyla- most are marine
Animal phylogeny & diversity
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Monophyletic; colonial flagellated protist
ancestor
1- Parazoa-Eumetazoa dichotomy:
sponges (Parazoa)~ no true tissues; all
other animals (Eumetazoa)~ true tissues
2- Radiata-Bilateria dichotomy: Cnidaria
(hydra; ‘jellyfish’; sea anemones) &
Ctenophora (comb jellies)~ radial body
symmetry; all other animals~ bilateral
body symmetry (also: cephalization)
Summary
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3 Domains- but textbooks are behind:
Bacteria, Archaea, and Eukarya
6 kingdom system in most texts:
Eubacteria, Archaea, Protista, Fungi,
Plantae, Animalia
classification now based on evolutionary
history