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Micrasterias
Salpingoeca
Climacostomum
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Coleochaete
orbicularis
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Kingdom Protista
Algae
Contribute to most of our fossil fuels
Generate 50-
oxygen
Used as food
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Outline
Phylum Chlorophyta (Green Algae)
Phylum Chrysophyta (Diatoms)
Phylum Rhodophyta (Red Algae)
Phylum Euglenophyta (euglenoids)
Phylum Pyrrhophyta (Dinoflagellates)
Phylum Phaeophyta (Brown algae)
Phylum Myxomycota
Phylum Dictyosteliomycota
Phylum Oomycota
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Features of Kingdom Protista
All members have eukaryotic cells.
Individual life cycles vary considerably, but
reproduction is generally by cell division and
sexual processes.
Most multicellular members produce some
motile cells.
General
Algae range in size
from microscopic,
single celled organisms
to large seaweed that
may be hundreds of
feet long.
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Energy
Algae are phototrophic autotrophs they are plant-like organisms because they perform PHOTOSYNTHESIS. Like plants, algae contain chlorophyll and produce their own carbohydrates while giving off oxygen as a by-product of the reaction.
Despite their diversity, all kinds of algae have some things in common:
1. Algae live wherever there is sufficient water. They grow in ponds, in salt water, in moist soil and even on the surface of ice.
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2. All known Phyla contain the light absorbing photosynthetic pigment chlorophyll in structures called chloroplasts.
Different types of algae also contain other forms of chlorophyll such as chlorophyll b, c or d. Each of these absorb different wavelengths of light.
3. Most have flagella at some point in their life
cycle.
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4. Algae cells often
contain pyrenoids,
organelles that
synthesize and store
starch.
Phylum Chlorophyta
The Green Algae
Includes about 7,500 species that occur in a rich variety of forms and occur in diverse, widespread habitats.
- Greatest variety found in freshwater lakes, ponds, and streams.
- Most have a single nucleus.
- Most reproduce both sexually and asexually.
- chl a, b
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Phylum Chlorophyta
Chlamydomonas
Common inhabitant of freshwater pools.
Pair of whip-like flagella on one end pull
the cell through the water.
Single, cup-shaped chloroplast with one or
two pyrenoids inside.
- Proteinaceous structures thought to
contain starch synthesis enzymes.
Chlamydomonas
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Chlamydomonas
Asexual Reproduction
Nucleus divides by mitosis, and cell
contents become two daughter cells within
the cellulose wall.
- Develop flagella and swim away.
Sexual Life Cycle of Chlamydomonas
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Phylum Chlorophyta
Ulothrix
Thread-like alga.
- Single row of cylindrical cells forming a
filament.
Basal cell functions as a holdfast.
Isogamy- gametes of identical size
and appearance
Ulothrix Life Cycle
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Phylum Chlorophyta
Spirogyra (Watersilk)
Common freshwater algae consisting of unbranched filaments of cylindrical cells.
- Frequently float in masses at the surface of quiet waters.
Asexual Reproduction
- Fragmentation of existing filaments.
Sexual Reproduction
- Papillae fuse and form conjugation tubes.
Spirogyra Sexual Reproduction
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Phylum Chlorophyta
Oedogonium
Epiphytic filamentous green alga.
- Each cell contains a large, netlike
chloroplast that rolls and forms a tube
around and toward the periphery of each
protoplast.
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