kingdom protista (“k. fruit salad”) protistans are not ... · pyrophyta (dinoflagellates) •...
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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
Note: These groups only represent a sample of protist diversity; many other lineages are not shown on the tree.
Why Dr. R. has a Love/Hate relationship with K. Protista
General Protistan Characteristics
1. habitat diversity2. free-living or symbiotic3. aerobic metabolism4. pellicle support structure5. 9+2 structure in cilia and flagella6. asexual and sexual reproduction7. cyst forming potential8. not specialized but highly complex
Ciliates
Multinucleated
Macro: metabolic and developmental issues
Micro: Sexual reproduction
High intracellular specialization:“Mouth, anus, excretion, locomotion, reproduction, behavior”
A ciliated protozoanFig. 11.18
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Ciliophora: Conjugation and Genetic Recombination
RhizopodaThe Ameba• Amoebas,
simplest pseudopod users
• Free-living and parasitic
• Can form cysts• Reproduce
asexually• Phagocytosis
Fig. 11.26
Actinopoda: Heliozoans and Radiolarians• Axopodia• Heliozoans : FW,
unfused silica or chitin
• Radiolarians: marine, fused silica
• Radiolaria ooze
Radiolarian skeleton
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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)• Marine phytoplankton• Unicellular, some colonial
• cellulose plates with perpendicular flagella• chlorophyll a, c, carotinoids• starch• Dinoflagellate blooms, red tides. PSP and Pfiesteria
Red Tides
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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
““BuddenbrockiaBuddenbrockia””
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
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Diatom Reproduction
a slime mold Figure 28.30 The life cycle of a cellular slime mold (Dictyostelium)
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
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
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Algae structurePneumatocysts:N2, O2, and Co2 gasSingular 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
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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
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Stinkhorn
Mycorrhizae- Important symbiosis with plant roots Lichens- Symbiotic associations of Fungi and Algae