The Awesome Algae

Why Awesome? Life as we know it, would never have evolved without them Produces most of the Earth’s oxygen (estimated 50-75% of all photosynthesis is done by algae) They also help remove huge amounts of carbon dioxide!

More awesomeness... The basis of most food chains in the ocean 3. Some are so cool, they can live in the snow...and look like blood They can glow (bioluminescence) 5. They may be the next source of fuel

And more awesomeness... 6. We use them to treat a heap of things: Stomach ulcers, lung ailments, high blood pressure, arthritis, and other health products

Even more 7. Used in hand lotion, toothpaste, to make plastics, waxes 8. Used in scientific laboratories to grow bacteria

9. Can provide a home for sea otters and many many many other species.

Can it get any more awesome? Yes. 10. They are also delicious They are used to make ice cream smooth, candy bars last longer Used in pickle relishes, salad dressing, chip dips, pancake syrup, egg nog, soup, meat dishes, candy, cake batter, pie filler, bakery jelly, doughnut glazes

Algae Photosynthetic organisms that live in streams, ponds, lakes, swamps, oceans, on damp tree trunks, in moist soil What must they live by? ____________________

Plant or Protist? Scientists have debated this one for a while Now we say that they are not plants, but protists Remember protist = eukaryotes that don’t fit in other kingdoms (the garbage pile)

Why are they like plants? Some algae, the “seaweeds” are _______________ Share many other characteristics with plants Giant kelp

Why are they protists? Many are ____________________organisms, such as phytoplankton Don’t have the specialized root, leave or stem structures found in land plants, although they can have structures that serve similar functions phytoplankton Bull kelp

Root-like, stem-like and leave-like structures Bull kelp with its hold-fast, stipe, blades and gas-filled bulb

Three Phyla of Algae The three phyla of algae that are largely multicellular are commonly known as “red algae”, “brown algae” and “green algae” The most important difference between them is their photosynthetic pigments Phylum Rhodophyta (Red algae) Phylum Phaeophyta (Brown algae) Phylum Chlorophyta Green algae

Green Algae Members of Phylum Chlorophyta, meaning “green plant” in Greek Share many characteristics with plants including photosynthetic pigments (chlorophyll a and b) and cell walls They also have reproductive cycles very similar to plants

Green Algae: Where and How Green algae can be found in fresh and salt water, and in moist areas on land They can be: Unicellular Colonial Multicellular

Unicellular Many species spend most of their lives as single cells Chlamydomonas is a typical unicellular green algae that grows in ditches, ponds and wet soils Chlamydomonas

Colonial Several species of green algae form colonies (groups of single cells that are joined together but show few specialized structures) Ex. Spirogyra is found in freshwater - It forms long threadlike colonies called filaments stacked like aluminum cans

Colonial Volvox cells are joined together by strands of cytoplasm. Can contain 500-5000 cells arranged to form hollow spheres Some cells are specialized for reproduction Borderlines colonial and multicellular

Multicellular Ulva, or “sea lettuce” is a bright green multicellular algae, common along rocky seacoasts Only two-cells thick, but tough enough to handle pounding waves

Reproduction in Ulva Has a life-cycle involving “alternation of generations” of two stages in it’s life: the diploid stage, the sporophyte (which is a _____________________ producing stage) alternates with the haploid stage, the gametophyte (which is a ______________________________ producing stage)

Alternation of Generations in Ulva