UNIT VII - CLASSIFICATION
• Formation of Organic Molecules
o Oparin/Haldane Hypothesis
 Primitive Earth’s atmosphere favored chemical
rxns that made _____________ compounds
from inorganic precursors
 Reducing/electron adding atmosphere would
enhance joining of molecules
 No _________ because no plants to do
photosynthesis
 Early oceans were an organic “soup”
 __________________ & UV radiation provided
energy for complex organic molecule formation
o Miller/Urey Experiment
 Tested Oparin/Haldane hypothesis
 Simulated atmosphere composed of water,
hydrogen, methane, & ammonia
 All ____________________________, nitrogen
bases, _______________ formed
 Hypothesis was supported
I. EARLY EARTH
I. EARLY EARTH
• Three Eons
 1st two described as ________________
o Archaean Eon & Proterozoic Eon
 Present day = Phanerozoic eon
o Paleozoic era, Mesozoic era, & Cenozic era
• Continental Drift
 Pangaea – “______________”
 Gondwana & Laurasia
• Mass Extinctions
• Biogeography
 Study of past & present distribution of species
I. EARLY EARTH
II. PHYLOGENY
• Phylogeny - _______________
history of an organism
• ______________________ - the
tracing of evolutionary relationships;
includes taxonomy
• Linnaean System
– ________________ nomenclature
– Hierarchical classification
• __________________ – taxonomic unit
II. PHYLOGENY
• ____________________
 Diagram showing patterns of
__________ characteristics among
organisms
 Homology vs. analogy...
o ________________ - likenesses
attributed to common ancestry
o USED IN CLADOGRAMS
o ________________ - likenesses
attributed to similar ecological roles
and natural selection
• Convergent evolution
 Species from __________________
evolutionary branches that resemble
one another due to
_________________ ecological
roles
II. PHYLOGENY
III. PROKARYOTES
III. PROKARYOTES
Classification Methods
 Domain Archaea
– Kingdom Archaebacteria
 Domain Bacteria
– Kingdom Eubacteria
Shape
 ___________ - spherical/round
 ___________- rod
 ___________ - helical/spiral
Gram Stain Reaction
 Positive
 Negative
Cell Wall
IV. PROKARYOTES - EUBACTERIA
 _________________________ - consists of polymers of modified sugars cross
linked by short polypeptides that vary
 ________________________ have no peptidoglycan
 Gram _________________
 Simpler cell walls
 _____ of peptidoglycan
 Peptidoglycan traps ___________
dye of Gram stain
 Gram __________________
 More complex cell walls
 _______ peptidoglycan
 Violet dye of Gram stain is easily rinsed;
bacteria will turn _______________
 Usually more threatening
Capsule
 Adherence & Protection
Pili
 Adherence & Conjugation
IV. PROKARYOTES – EUBACTERIA
Motility
• Flagella
• Helical shape
 Spirochetes
• Slime
• Taxis
 Stimulus
IV. PROKARYOTES – EUBACTERIA
• Have a ___________ region that contains the DNA
• May contain _______________, small rings of DNA
consisting of a few genes which are separate from the
bacterial chromosome
• _______________________ - bacteria asexual
reproduction
• “Sexual reproduction” – not really sexual
reproduction……more like modes of genetic transfer
 _____________________
 _____________________
 _____________________
• Endospore
 Bacterial “hibernation”
IV. PROKARYOTES – EUBACTERIA
Nutrition – 4 Groups
• __________________________
 Photosynthetic
 Use light to drive the synthesis of organic
compounds
 Cyanobacteria
• __________________________
 Oxidize inorganic chemicals for energy
 Obtain carbon from CO2
• __________________________
 Use light to generate ATP
 Must obtain carbon in an organic form
• __________________________
 Consume organic molecules for both energy
and carbon
 Saprobes - decomposers
 Parasites
IV. PROKARYOTES – EUBACTERIA
• Metabolism
o Nitrogen fixation
 Conversion of atmospheric nitrogen ______ to
ammonium ____________
o Oxygen relationships
 ________________________________ – must
use O2 for cellular respiration and cannot grow
w/o it
 ________________________________ – use
O2 if it is present but can also grow via
fermentation in an anaerobic environment
 ________________________________ – are
poisoned by O2; some live exclusively by
fermentation or some extract chemical energy
by anaerobic respiration
IV. PROKARYOTES – EUBACTERIA
Prokaryotic Ecology
• Decomposers
• Nitrogen Fixation
• Symbiosis
 ___________________________ –
both organisms benefit
 _______________________ – one
organism benefits while neither
harming or helping another organism
 _______________________ – one
organism benefits at the expense of
the host
IV. PROKARYOTES – EUBACTERIA
Bacterial Pathogenesis
•
Koch’s Postulates – Criteria for bacterial disease confirmation
1)
2)
3)
4)
•
Opportunistic
 Normal residents of host; cause illness when defenses are weakened
•
Exotoxins
 Bacterial proteins that can produce disease w/o the prokaryote present (botulism)
•
Endotoxins
 Components of gram negative membranes (Salmonella)
V. ORIGINS OF EUKARYOTIC CELLS
• _______________________________ (AKA “Endosymbiont Theory”)
• Margulis
• _______________________ and ________________________ were
formerly from small prokaryotes living within larger cells
V. ORIGINS OF EUKARYOTIC CELLS
Support for Endosymbiotic Theory
• Similarities between _______________ and the
________________ & ________________ of eukaryotes
– Mitochondria & chloroplasts are appropriate ___________ to be
descendents of bacteria
– Inner membranes of chloroplasts & mitochondria have several
_______________ & transport systems that resemble those found on
plasma membranes of prokaryotes
– Replication of Mitochondria/Chloroplasts
• Split similar to ____________________________
– _______________________________ DNA molecule not associated
with histones or other proteins
– Ribosomes
EUKARYOTES
VI. KINGDOM PROTISTA
•
•
•
•
Very diverse
All are _____________________________
Mostly _____________________________
Protists are usually classified according to
the eukaryotic kingdom the protist is most
like and its nutrition mode
 ___________________
 Ingestive
 Protozoa
 ___________________
 Photosynthetic
 Algae
 ____________________
 Absorptive
 Slime Molds
VI. KINGDOM PROTISTA
Protist Phylogeny
VI. KINGDOM PROTISTA, cont
Protist Systematics
• Diplomonads
 Lack mitochondria, cell walls
 Giardia lamblia
 Trichomonas vaginalis
• Euglenoids
 Most are heterotrophic; may be
autotrophic
 Most lack cell wall, but have a
structural protein layer under cell
membrane
 Flagellated
 Many have “eyespot”
 Euglena
 Trypanosoma
VI. KINGDOM PROTISTA - Systematics, cont
• Alveolates
 Contain small sacs called alveoli; may
help regulate water, ion concentration
 Dinoflagellates – phytoplankton, also
known as “spinning algae”
 Red Tides
 Ciliates – Paramecium, Stentor
 Apicomplexa - all parasitic; lack cilia,
flagella
 Plasmodium
 Toxoplasma
VI. KINGDOM PROTISTA - Systematics, cont
• Stramenopila
•
•
Heterokonts – “different flagella”
Water molds (decomposers), mildews (parasitic),
algae (photosynthetic)
 Diatoms
 Photosynthetic; make up most of Earth’s
plankton
 Have glass-like silicon shells
 Brown Algae
 Golden Algae
VI. KINGDOM PROTISTA - Systematics, cont
• Foraminiferans
 Ca Carbonate shells
 Dead foraminiferans settle on ocean
floor; shells become chalk
 White Cliffs of Dover
• Rhodopyhta
 Red algae
 Mostly multicellular
• Chlorophyta
 Green Algae
 Volvox
 Spirogyra
 Chlamydomonas
 Unicellular; may be colonial
 Chloroplasts, cell walls of cellulose
 Gave rise to land plants
VI. KINGDOM PROTISTA - Systematics, cont
• Amoebozoa
 All have pseudopods
 Amoeba
May be parasitic
Entamoeba histolytica
 Plasmodial Slime Molds
Feeding stage is a
multinucleate mass
known as a plasmodium
 Cellular Slime Molds
Feeding stage is single
amoeboid cell
VII. KINGDOM FUNGI
VII. KINGDOM FUNGI
Characteristics of Fungi
• Multicellular (except for yeast)
• ___________________ by
absorption; releases
___________________that
helps the fungus digest the food
outside its body
• Ecological roles
– Decomposers (saprobes)
– Parasites
– Mutualistic symbionts (lichens)
• Hyphae - body filaments
– __________________ - network
of hyphae that the fungus uses for
feeding
• ___________ cell walls
• Reproduce by ___________
VII. KINGDOM FUNGI, cont
Life Cycle
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VII. KINGDOM FUNGI, cont
Classification
• Phylum Chytridiomycota
 Most closely related to protists;
considered to be most primitive
member of Kingdom Fungi
 Aquatic fungi
• Phylum Zygomycota
 Food mold; Rhizopus
 Mycorrhizae
 Produce spores from zygote
surrounded by thick covering
called zygosporangium; may
remain dormant for months;
resistant to extreme conditons
VII. KINGDOM FUNGI - Classification, cont
• Phylum Ascomycota
 Sac fungi
 Yeasts, truffles, morels, Sordaria
 Produce sexual and asexual
spores
 Ascus – sexual spore
 Conidia – asexual spore
• Phylum Basidiomycota
 Club fungi
 Mushrooms, puffballs, bracket
fungi
 Basidiocarp – haploid hyphae fuse,
meiosis occurs, formation of
basidospores
VII. KINGDOM FUNGI, cont
Specialized Life Styles
• Molds
 Used to be classified as Deuteromycota or
“Imperfect Fungi”
 No known sexual stage
 Penicillium
• Yeasts
 Unicellular
 Reproduce asexually; budding
 Saccharomyces
• Lichens
 Mutualistic relationship with algae, cyanobacterium
 Sensitive to air pollution
• Mycorrhizae
 Mutualistic relationship found in 95% of all plants
 Increases absorptive surface of roots