Protistans are NOT monophyletic General Protistan

Kingdom Protista (“K. Fruit Salad”)
•
•
•
•
100,000 living species, 35,000 fossilized members
Ancestors to metazoans: plants, fungi, animals
Low specialization, high complexity
Two distinguishing features from Moneran
ancestors:
– Compartmentalized cell structure
– Increased genomic size
Protistans are NOT monophyletic
Why Dr. R.
has a
Love/Hate
relationship
with K.
Protista
Note: These groups only represent a sample of protist diversity; many
other lineages are not shown on the tree.
Ciliates
General Protistan Characteristics
1. habitat diversity
2. free-living or symbiotic
3. aerobic metabolism
4. pellicle support structure
5. 9+2 structure in cilia and flagella
6. asexual and sexual reproduction
7. cyst forming potential
8. not specialized but highly complex
A ciliated protozoan
Multinucleated
Macro: metabolic and
developmental issues
Micro: Sexual
reproduction
High intracellular
specialization:
“Mouth, anus, excretion,
locomotion, reproduction,
behavior”
Fig. 11.18
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Ciliophora: Conjugation and Genetic
Recombination
Rhizopoda
The Ameba
Fig. 11.26
• Amoebas,
simplest
pseudopod users
• Free-living and
parasitic
• Can form cysts
• Reproduce
asexually
• Phagocytosis
Radiolarian skeleton
Actinopoda: Heliozoans and Radiolarians
• Axopodia
• Heliozoans : FW,
unfused silica or
chitin
• Radiolarians:
marine, fused silica
• Radiolaria ooze
2
Foraminifera (Forams)
• Most are marine
• Porous,
multichambered shell
of CaCO3
• 90% of described
species are fossils
• Deepsea species
• 1/3 of seafloor- One
species of Foram
Chalk, limestone, etc
Fig. 11.27b
Pyrophyta (Dinoflagellates)
Red Tides
• Marine phytoplankton
• Unicellular, some colonial
•
•
•
•
cellulose plates with perpendicular flagella
chlorophyll a, c, carotinoids
starch
Dinoflagellate blooms, red tides. PSP and Pfiesteria
3
Swimming with bioluminescent dinoflagellates
Apicomplexa (Sporozoa): The life
history of Plasmodium, the cause of
malaria.
leading
cause of
death for
humans
~3
million/
year!
What happens with climate change?
The problem of the Myxozoa
“Buddenbrockia”
Buddenbrockia”
Diatoms- class Bacillariophyta
• Unicellular
• Centric and Pennate
• Shell (Frustule) walls made of
Silica (SiO2)
– Epitheca and hypotheca
• Reproduction (asexual and
sexual)
• Auxospores
• Diatomaceous/Siliceous Ooze
4
Diatom Reproduction
a slime mold
The Macroscopic Algae
• Plant evolution begins in the sea
• Single celled
Multicelled colonies
– But still have very little specialization between
cells
• Three divisions of algae- all can be seen in tide
pools
– Rhodophyta- Red Algae
– Phaeophyta- Brown Algae
– Chlorophyta- Green Algae
Figure 28.30 The life cycle of a cellular slime mold (Dictyostelium)
The 3 groups of
Algae
• Rhodophyta- Red Algae
– Chl. a, other accessory
pigments, storage is
Floridean starch
• Phaeophyta- Brown Algae
– Chl. a & c, other pigments,
storage is Laminarin
• Chlorophyta- Green Algae
– Chl. a & b, other pigments,
storage is Starch
5
Algae structure
Pneumatocysts:
N2, O2, and Co2 gas
Singular and large, or small
and many
Phaeophyta and the Evolutionary
Adaptations of Seaweeds to a Physically
Stressful Environment
• Multicellular with a minor degree of
specialization
• Structural adaptations of thallus:
holdfast, stipe, blades, gas bladders
(pneumatocysts)
• Chemical adaptations:
– Cellulose walls w/ polysaccharides
– may incorporate calcium carbonate
• 3 Reproductive Cycles: Haplontic
(zygotic), Diplontic (gametic) or
Alternation of Generations
(diplohaplontic,sporic cycle)
Kelp Beds and Forests
• Found in cold, temperate regions only.
• Large brown algae= kelp.
• Kelps obtain nutrients from water, so
depend on turbulence to renew waters to
avoid depletion.
• Form extensive 3-D habitat with several
vertical layers= High species diversity
Rhodophyta: distant relatives to
Phaeophyta…a separate kingdom?
• No flagellated stage
• mostly marine, tropical
• Chlorophyll a, carotinoids,
phycobilins (phycoerythrin)
– Primary endosymbiosis
• storage = floridean starch
• cell walls are cellulose with agar
and carageenan
• Broad coastal distribution
• Alternation of generations is
common, rely on water currents
Chlorophyta: share a common ancestor
with terrestrial plants
• Cyanobacteria and primary
endosymbiotic theory…
Chlorophyll a, b, carotinoids,
• Marine, FW, soil, freeliving
and symbiotic
• Diverse body plans, colonial,
multicellular
• storage=starch
• cell wall = cellulose
• Ulva: isomorphic alt of gen
– Biflagellated gametes
– conjugation
6
The life cycle of Laminaria: an example of alternation of
generations
Kingdom Fungi
• Decomposers make the world go round
• Recycle nutrients from the dead to the
living
• Symbiosis with roots allow nearly all plants
to absorb nutrients and water better.
• Food Source, Drugs, Baking, Wine/Beer
• Are Heterotrophs
Fungi and Bacteria- the decomposers
• Long evolutionary history
• 400 mya- 25 ft high fungi?
• On land before large trees
and vertebrates
7
Decomposers
Fungi Diversity
8
Stinkhorn
Mycorrhizae- Important symbiosis with plant roots
Lichens- Symbiotic associations of Fungi and Algae
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