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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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