1030 bio 2
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- Photosynthetic protists have six major phyla:
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1. Phylum Phyrrhophyta (dinoflagellates)
2. Phylum Euglenophyta (euglenoids)
3. Phylum Chrysophyta (diatoms and golden algae)
4. Phylum Rhodophyta (red algae)
5. Phylum Phaeophyta (brown algae)
6. Phylum Chlorophyta (green algae) - Six characteristics of Phylum Phyrrhophyta:
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1. unicellular
2. mostly marine
3. usually 2 flagella
4. most have chlorophyll a and c
5. exoskeleton of plates of cellulose
6. asexual reproduction - most of the organisms in Phylum Phyrrhophyta are zooxanthellae, which is what? Where do they live, what do they make there?
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symbionts (live in a mutually beneficial relationship) in other organisms
zooxanthellae in CORALS, do photosynthesis and help make corals very productive - an important role to Phylum Phyrrhophyta is also bioluminescent. What is this?
- many plankton dinoflagellates emit light when disturbed. it creates sparkling waves and glowing wakes of ships at night
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predatory dinoflagellates:
how? Why?
Example? -
generate toxins that they use to kill marine life
pfiesteria pisicida - What are red tides?
- population explosions that can color the water with pigmented dinoflagellate cells. red tides kill marine life due to the high concentration of toxins
- Phylum Euglenophyta has 9 characteristics:
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1. unicellular
2. mostly freshwater
3. some photosynthetic, some not
4. some are faculative heterotropic
5. have a pellicle coat
6. asexual reproduction
7.members of freshwater food chains
8. NOT a synapomorphy that defines a clade
9. example: Euglena - What is a facultative heterotroph?
- a photosynthetic form that can switch to being heterotrophs if kept in the dark, and switch back to autotrophs if given enough light
- What is a pellicle coat?
- a helical, flexible protein coat on the outside of the shell
- in phylum Chrysophyta, there are two overall characteristics:
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1. have chlorophyll a and c (chloroplasts are like brown algae and dinoflagellates)
2. they make chrysolaminarin - What is chrysolaminarin?
- a unique carbohydrate used for energy storage
- Phylum Chrysophyta - Diatoms: 8 characteristics:
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1. unicellular
2. 11,500 + species known
3. occur in plankton
4. lack flagella
5. cell wall = double shells of silica that fit together like a box and lid
6. shells have intricate designs
7. mostly asexual reproduction
8. CAN undergo gametic meiosis (usually diploid most of life) - importance of diatoms (2):
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1. "grass of the sea" - abundant members of plankton, perform a large % of photosynthesis done in ocean
2. "diatomaceous earth" (fossil deposits of cell walls), mined and used for pest control - Phylum Chrysophyta - golden algae: 5 characteristics:
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1. unicellular (often colonial)
2. freshwater protists
3. yellow and brown carotenoid and xanthophyll pigments (gives golden color)
4. usually two flagella
5. can form cysts - Phylum Rhodophyta has 8 characteristics:
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1. mostly marine and mostly multicellular
2. no flagella
3. chloroplasts have phycobilins and chlorophyll a
4. characteristic of chyanbacteria (1st photosynthetic organism)
5. SO chloroplasts seem derived from an endosymbiotic relationship with cynobacteria - importance of red algae (2):
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1. coral reefs are partially made of coralline red algae
2. agar and carrageenan - cell wall componenets are extracted and used as thickeners (ice cream) - Phylum Phaeophyta has 5 characteristics:
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1. ~1500 species
2. multicellular, large, including kelps
3. chloroplasts have chlorophylls a and c
4. (sexual) alternation of generations and sporic meiosis - Phylum Phaeophyta: focus on kelps (4):
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1. complex, branching vascular system = plants
2. "kelp forests" (impt to shallow water inhabitants)
3. harvested for alginates (cell wall materials), used for thickners - Phylum Chlorophyta has 5 characteristics:
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1. diverse
2. unicellular --> multicellular species
3. chlorophyll a and b
4. some symbionts
5. asexual reproduction ALSO alternation of generations with sporic meiosis - Phylum Chlorophyta: importance (5):
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1. base of food chain
2. possible nutritional supplement
3. plants evolved from a line of green algae
4. multicellular forms = nonvascular plants
5. DNA sequencing supports clade of plants and green algae