Biodiversity

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Biodiversity
2
PLANTS
Fig. 20.16, p. 326
Monera Protista Fungi Plantae Animalia
ANIMALS
flowering plants
arthropods
chordates
annelids
conifers
echinoderms
cycads
mollusks
ginkgo
ribbon worms
ferns
FUNGI
gnetophytes
roundworms
horsetails
flatworms
rotifers
mosses, liverworts, hornworts
lycophytes
club fungi
cnidarians
whisk ferns
sac fungi
comb jellies
sponges
Trichoplax
zygomycetes
red algae
green algae
brown algae
chytrids
ciliated protozoans
flagellated protozoans
diatoms
dinoflagellates
chrysophytes
euglenoids
sporozoans
PROTISTANS
water molds
slime molds
amoeboid protozoans
eubacteria
Five kingdom system
MONERANS
archaebacteria
chemical origin of life
3
Fig. 20.17, p. 327
Three domains
EUBACTERIA
ARCHAEBACTERIA
EUKARYOTES
4
Fig. 20.18, p. 328
Six kingdom system
EUBACTERIA
ARCHAEBACTERIA
PROTISTA
FUNGI
PLANTAE
ANIMALIA
5
Fig. 21.7,
ARCHAEBACTERIAL LINEAGE
ARCHAEBACTERIA
ARCHAEBACTERIA
Extreme halophiles
Methanogens
Extreme thermophiles
EUKARYOTES
ORIGINS OF EUKARYOTES
Animals
EUKARYOTES
Heterotrophic protistans
Heterotrophic protistans
Fungi
Photosynthetic protistans
ANCESTORS OF EUKARYOTES
Plants
EUBACTERIA
ORIGIN OF PROKARYOTES
Oxygen-producing photosynthetic eubacteria (e.g.,
cyanobacteria)
EUBACTERIA
Other photosynthetic eubacteria
EUBACTERIAL LINEAGE
3.8 billion years ago
3.2 billion years ago
2.5 billion years ago
1.2 billion years ago
900 million years ago
435 million years ago
present
Eubacteria and archaebacteria
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Archaebacteria
halophiles salt lovers
thermophiles heat lovers strict anaerobes
methanogens use H2 for electrons produce
methane strict anaerobes
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Eubacteria
Generally very small
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Eubacteria
Morphologically diverse
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Eubacteria
Metabolically diverse

• photoautotrophic
• chemoautotrophic
• photoheterotrophic
• chemoheterotrophic

self-feeders carbon from CO2
Nitrogen fixation
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Viruses
e Lysis of host cell is induced infections
particles escape.
LYTIC PATHWAY
d Tail fibers and other parts are added to coats.
a Virus particles bind to wall of suitable host
cell. Viral genetic material enters cell
cytoplasm.
c Viral protein molecules are assembled into
coats DNA is packaged inside.
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LYSOGENIC PATHWAY
b Viral DNA directs host cell machinery to
produce viral proteins and copies of viral DNA.
a-1 In a lysogenic pathway, viral DNA usually
becomes integrated into the bacterial chromosome.
a-4 Viral DNA is excised from the chromosome.
a-2 Prior to prokaryotic fission, the chromosome
and integrated viral DNA is replicated.
a-3 AFTER binary fission, each daughter cell
will have recombinant DNA.
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HIV
13
Fig. 21.7, p. 340-41
ARCHAEBACTERIAL LINEAGE
ARCHAEBACTERIA
ARCHAEBACTERIA
Extreme halophiles
Methanogens
Extreme thermophiles
EUKARYOTES
ORIGINS OF EUKARYOTES
Animals
EUKARYOTES
Heterotrophic protistans
Heterotrophic protistans
Fungi
Photosynthetic protistans
ANCESTORS OF EUKARYOTES
Plants
EUBACTERIA
ORIGIN OF PROKARYOTES
Oxygen-producing photosynthetic eubacteria (e.g.,
cyanobacteria)
EUBACTERIA
Other photosynthetic eubacteria
EUBACTERIAL LINEAGE
3.8 billion years ago
3.2 billion years ago
2.5 billion years ago
1.2 billion years ago
900 million years ago
435 million years ago
present
Protistans
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Protists

• Where would you find protists?
• How would they make a living?

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Protistans

• A diversity of forms
• Flagellated
• Amoeboid
• Ciliates
• Sporozoans
• Dinoflagellates
• Stramenopiles
• Green algae

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Flagellated
Euglena
Trypanosome
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Trypanosoma brucei sleeping sickness
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Genetic variation (gene conversion)
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Amoeboid
radiolarians (silica shell)
naked amoebas
foraminiferans (calcium carbonate shell)
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White cliffs of Dover 200 myr old deposits
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Ciliates
Paramecium
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Sporozoans
Plasmodium falciparum life cycle
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Sporozoans
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Dinoflagellates
Dinoflagellates (red tides)
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Stramenopiles
brown algae (kelp)
parasitic water mold
downy mildew
diatoms
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Green algae
green algae
halimeda
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Fig. 21.7, p. 340-41
ARCHAEBACTERIAL LINEAGE
ARCHAEBACTERIA
ARCHAEBACTERIA
Extreme halophiles
Methanogens
Extreme thermophiles
EUKARYOTES
ORIGINS OF EUKARYOTES
Animals
EUKARYOTES
Heterotrophic protistans
Heterotrophic protistans
Fungi
Photosynthetic protistans
ANCESTORS OF EUKARYOTES
Plants
EUBACTERIA
ORIGIN OF PROKARYOTES
Oxygen-producing photosynthetic eubacteria (e.g.,
cyanobacteria)
EUBACTERIA
Other photosynthetic eubacteria
EUBACTERIAL LINEAGE
3.8 billion years ago
3.2 billion years ago
2.5 billion years ago
1.2 billion years ago
900 million years ago
435 million years ago
present
Fungi
56,000 known species but most understudied group
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Fungi

• Heterotrophic eukaryotes
• Saprobes (eat non-living organic matter)
• Parasites
• Symbioses
• Lichens
• Mycorrhizae
• Major role as decomposers

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Fig. 24.4
After nuclear fusion, the club-shaped structure
(now 2n) will produce and bear haploid spores at
the four tips of the cell.
club fungi
Diploid Stage
nuclear fusion
meiosis
Haploid Stage
spore (n)
Club-shaped structures having two nuclei (n n)
form at the margin of each gill.
Spores are released.
hypha in mycelium
Each germinating spore gives rise to a hypha that
grows and becomes a branching mycelium.
gills
cap
stalk
hypha
After cytoplasmic fusion, a dikaryotic (n n)
mycelium gives rise to spore-bearing bodies
(e.g., mushrooms).
cytoplasmic fusion
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zygomycetes
zygospore (2n)
Diploid Stage
nuclear fusion
meiosis
50 µm
Haploid Stage
spores (n)
Zygospore
Spore sac
germinating zygospore
young zygospore
mycelium develops from germinated spore
spores (n)
gametangia fusing
stolon
rhizoids
ASEXUAL REPRODUCTION (mitosis)
contact between hyphae of two mating strains
Fig. 24.6, p. 396
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sac fungi
ascospore (sexual spore)
spore sac
ascoscarp
ascoscarp
spore-bearing hypha of this ascoscarp
conidia (chains of asexual spores)
budding yeast cell
Fig. 24.7, p. 397
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Fig. 24.8, p. 397
roundworm
noose formed by hypha
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Largest organism

• 3.4 square miles in size
• covers 2,200 acres of land in the Blue Mountains
  of eastern Oregon
• as large as 1,665 football fields combined
• Armillaria ostoyae

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Fig. 21.7, p. 340-41
ARCHAEBACTERIAL LINEAGE
ARCHAEBACTERIA
ARCHAEBACTERIA
Extreme halophiles
Methanogens
Extreme thermophiles
EUKARYOTES
ORIGINS OF EUKARYOTES
Animals
EUKARYOTES
Heterotrophic protistans
Heterotrophic protistans
Fungi
Photosynthetic protistans
ANCESTORS OF EUKARYOTES
Plants
EUBACTERIA
ORIGIN OF PROKARYOTES
Oxygen-producing photosynthetic eubacteria (e.g.,
cyanobacteria)
EUBACTERIA
Other photosynthetic eubacteria
EUBACTERIAL LINEAGE
3.8 billion years ago
3.2 billion years ago
2.5 billion years ago
1.2 billion years ago
900 million years ago
435 million years ago
present
435 mya plants invade the land
Multicelled photoautotrophs
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Innovations facilitating the invasion

• nonvascular to vascular
• early plants like bryophytes are nonvascular
• well developed root and shoot systems
• xylem and phloem
• lignin deposition, cuticle, stomata

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Innovations facilitating the invasion

• From haploid to diploid dominance

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Reproduction in algae
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A thick-walled resistant zygote develops.
Zygote (cross-section)
Diploid Stage
Meiosis and Germination
Nuclear Fusion
Hapoid cell ( strain)
Haploid Stage
Hapoid cell (- strain)
Mitosis occurs. Whether the resulting cells
develop into spores or gametes will depend on
environmental conditions.
Cytoplasmic Fusion
SEXUAL REPRODUCTION Mainly when nitrogen levels
are low and light is of a certain quality and
intensity, the cells develop into gametes.
ASEXUAL REPRODUCTION
ASEXUAL REPRODUCTION
More spores are produced.
More spores are produced.




Fig. 23.22, p. 389
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Reproduction in bryophytes
40
Mature sporophyte (spore-producing structure and
stalk), still dependent on gametophyte.
Zygote grows, develops into a sporophyte while
still attached to gametophyte.
zygote
Diploid Stage
Fertiliztion
Meiosis
Haploid Stage
Spores form by way of meiosis and are released.
Sperm reach eggs by moving through raindroips or
film of water on the plant surface.
Spores germinate. Some grow and develop into male
gametophytes.
rhizoid
sperm-producing structure at shoot tip of male
gametophyte.
egg-producing structure at shoot tip of female
gametophyte.
Other germinating spores grow and develop into
female gametophytes.
Fig. 25.4, p. 406
41
Reproduction in angiosperms
42
Fig. 25.19, p. 417
a flowering stem of the mature sporophyte (2n)
ovules inside ovary
seeding
pollen sac, where each one of many cells will
give rise to microspores
seed coat
cell in ovule that will give rise to one megaspore
embryo
endosperm
seed
Diploid Stage
Meiosis
Meiosis
Double Fertilization
Haploid Stage
Meiosis and two rounds of mitosis without
cytoplasmic division produce single cell with
multiple nuclei. Cytoplasmic divisions
result in a female gametophyte, a sac of haploid
cells within the ovule.
Meiosis and cytoplasmic divisions result in four
haploid (n) microspores, which develop into
pollen grains.
After pollination occurs, a pollen grain develops
into a pollen tube, which grows toward the ovary.
The tube contains two sperm it is the mature
male gametophyte.
male gametophyte
pollen tube
sperm (n)
sperm (n)
Pollen is released.
The pollen tube enters an ovule. One sperm will
fertilize the egg, one will fertilize the
endosperm-producing cell.
cell from which endospoerm will form
egg
The female gametophyte has seven cells.
(line of cut of diagram at left)
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Fig. 25.2, p. 404
zygote
SPOROPHYTE (2n)
GAMETOPHYTE (n)
GREEN ALGA
BRYOPHYTE
FERN
GYMNOSPERM
ANGIOSPERM
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Innovations facilitating the invasion

• From haploid to diploid dominance
• large sporophytes protect gametophytes and young
  sporophytes
• advantage in a dry habitats, protect pollen/eggs
  and seeds until the environment is right for
  dispersal.

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Innovations facilitating the invasion

• Pollen and seeds
• with two types of spores, one (pollen) can be
  very small, facilitating dispersal
• seeds can protect young developing sporophytes
• seeds can package some nutrition with young
  embryo to give it a head start n a new environment

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Fig. 25.3, p. 405
FLOWERING PLANTS
?
CONIFERS
CYCADS
PROGYMNOSPERMS
GINKGOS
FERNS
HORSETAILS
ancestral green algae
LYCOPHYTES
RHYNIOPHYTES
BRYOPHYTES
PALEOZOIC
MESOZOIC
CENOZOIC
Silurian
Ordovician
Devonian
Carboniferous
Permian
Triassic
Jurassic
Cretaceous
present
505
435
410
360
290
240
205
138
65
Time (millions of years ago)
seed-bearing vascular
seedless, vascular
mosses, liverworts, hornworts seedless,
non-vascular
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Fig. 21.7, p. 340-41
ARCHAEBACTERIAL LINEAGE
ARCHAEBACTERIA
ARCHAEBACTERIA
Extreme halophiles
Methanogens
Extreme thermophiles
EUKARYOTES
ORIGINS OF EUKARYOTES
Animals
EUKARYOTES
Heterotrophic protistans
Heterotrophic protistans
Fungi
Photosynthetic protistans
ANCESTORS OF EUKARYOTES
Plants
EUBACTERIA
ORIGIN OF PROKARYOTES
Oxygen-producing photosynthetic eubacteria (e.g.,
cyanobacteria)
EUBACTERIA
Other photosynthetic eubacteria
EUBACTERIAL LINEAGE
3.8 billion years ago
3.2 billion years ago
2.5 billion years ago
1.2 billion years ago
900 million years ago
435 million years ago
present
Animals
Multicelled heterotrophs
Cambrian - 550 MYA, major radiation of animals
with hard parts
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Cambrian revolutionthe biological big bang
Starting 530 mya almost all modern phyla and
classes of skeletonized marine animals suddenly
appear in the fossil record within 5-30 my
Hallucigenia
49
Animalia

• Major evolutionary innovations (review of lab)
• Major invertebrate phyla

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Evolutionary innovations

• Body symmetry and cephalization

radial
bilateral
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Cephalization
posterior
dorsal
Advantages?
ventral
anterior
52
Evolution of the gut and body cavity

• Gut tubular or sac-like region specialized for
  food digestion (complete digestive systems have
  two openings)
• Acoelomate ? pseudocoelomate ? coelomate

53
Fig. 26.4a, p. 425
epidermis
gut cavity
no body cavity region between gut and body wall
packed with organs
acoelomates
54
Fig. 26.4b, p. 425
epidermis
gut cavity
unlined body cavity (pseudocoel) around gut
pseudocoelomates
55
gut cavity
Fig. 26.4c, p. 425
epidermis
peritoneum
lined body cavity (coelom) lining also holds
internal organs in place
coelomates
56
Segmentation

• Repeating units -- bilateral body plan
• Segment - evolutionary potential
• Addition, subtraction, or fusion of segments
• Segment modification and specialization

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Porifera - Sponges

• No symmetry, no real tissues/organs
• Plastic cell differentiation
• Silica or calcium carbonate spicules stiffen body

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Fig. 26.7a, p. 427
water out
glasslike structural elements
amoeboid cell
pore
central cavity
semifluid matrix
flattened surface cells
water in
flagellum
microvilli
nucleus
Collar cell
62
Sexual reproduction
Also asexual reproduction via fragmentation
63
Cnidaria
anthozoans
scyphozoans
hydrozoans
anemone
hydra
jellyfish
64
outer epithelium (epidermis)
mesoglea
inner epithelium (gastrodermis)
medusa
mouth
mouth
polyp
outer epithelium
mesoglea
inner epithelium
65
capsules lid at free surface of epidermal cell
exposure of barbs on discharged thread
trigger (modified cilium)
barbed thread inside capsule
nematocyst (capsule at free surface of epidermal
cell)
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Ctenophora
weak-swimming predators no nematocysts comb-beari
ng Cells with multiple cilia mesoderm
68
Platyhelminthes (flatworms)
turbellarians
tapeworms
flukes
bilaterally symmetric, cephalized, acoelomates
scavengers, parasites, most are hermaphrodites,
organ systems
69
Nemertea (ribbon worms)
bilateral soft-bodied predators circulatory
system, complete gut, venom-delivering proboscis,
separation of the sexes
70
Nematoda (round worms)
pseudocoelomate worms
pharynx
ring of nerves
intestine
false coelom
ovary (eggs develop here)
cuticle over epithelial tissue and muscle cells
pore (sperm enter and eggs are released through
this one)
anus
71
Rotifera small (lt 1mm) pseudocoelomates
well developed organ systems
feed on bacteria/algae
Fig. 26.22, p. 436
72
Coelomates
Early protostome embryo. Its four cells are
undergoing cleavages oblique to the original body
axis
Early deuterostome embryo. Its four cells are
undergoing cleavages parallel with and
perpendicular to the original body axis
In-text, p. 436
73
How a coelom forms in a protostome embryo
pouch will form mesoderm around coelom
developing gut
coelum
solid mass of mesoderm
How a coelom forms in a deuterostome embryo
developing gut
In-text, p. 436
74
Mollusca (protostome)
soft bodies most have a hard shell secreted from
soft tissues small coelom
pelecypods
cephalopods
gastropods
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76
Annelida (protostome)
segmented coelomates each segment has repeated
units of muscles, blood vessels, nerves water
permeable cuticle complex organ systems diversity
of forms
77
Arthropoda (protostome)
A successful group!
78
Arthropoda (protostome)
Chelicerates spiders and relatives
Uniramians centipedes, millipedes, insects
Crustaceans barnacles, lobsters
79
Scutigera House centipede
80
Secrets to success of the arthropods

• hardened exoskeletons
• jointed appendages
• fused and modified segments
• respiratory structures
• specialized sensory structures
• division of labor (metamorphosis)

81
Echinodermata (deuterostome)
body wall bears calcium carbonate spines,
spicules, or plates well developed internal
skeleton radial with some bilateral
characteristics bilateral larvae decentralized
nervous system tube feet
82
Arthropods
Fig. 26.45, p. 452
Annelids
segmented body
Mollusks
mouth
coelom
anus
head
false coelom
Roundworms
complete digestive system
bilateral symmetry, cephalization
unsegmented body
Flatworms
no coelom (no cavity between gut and body wall)
mouth
radial symmetry, no cephalization
saclike gut
Cnidarians, comb jellies
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Chordata (deuterostome)
notochord, dorsal nerve cord, muscular pharynx
with gill slits, tail
Urochordata (tunicates)
Vertebrata (vertebrates)
Cephalochordata (lancelets)