Aquatic Plants – Green, Red, and Brown Algae www.onacd.ca

Green Algae 6000 species single cells colonies long filaments. Chlamydomonas Spirogyra Ulva

Green Algae aquatic (freshwater or marine) or terrestrial form symbiotic relationships with fungi to form lichens. Caulerpa – an invasive seaweed Algal bloom Volvox

Characteristics of Green Algae chlorophyll a & b (green color) Some have flagella for movement cell walls with cellulose

Characteristics of Green Algae Sexual reproduction: go through 2 different life stages using a method called “alternation of generations Asexual reproduction: by fission, fragmentation or zoospores (motile spores)

Alternation of Generations A life cycle in which there are two distinct life stages that occur alternately for a species Stage 1 Diploid (2N – each cell has two sets of chromosomes) Called the sporophyte Produce gametes (= sex cells = haploid cells) by meiosis Stage 2 Haploid (1N – each cell has one set of chromosomes) Called the gametophyte Fuse to form a sporophyte (= zygote = diploid cells) by fertilization

Chlamydomonas Characteristics Unicellular Motile, 2 equal flagella Occur in stagnant water and damp soil, fresh water and salt water, even in snow! Have a nucleus inside their chloroplast Possess two small vacuoles which function to remove waste Have a light sensitive, red pigment spot which allows the cells to swim towards light

Chlamydomonas Life Cycle Take a good look at the diagram below of the life cycle of Chamydomonas which is an example of alternation of generations. Note the diploid (2N) and the haploid (1N) stages of its life. Diploid (2N)

Spirogyra Algal cells are joined end to end to form filaments (multicellular) Mostly freshwater Generally free floating Reproduces asexually by fragmentation and sexually by conjugation Does not form gametes, therefore does not go through alternation of generations Undergo conjugation – exchange of genetic information

Ulva (sea lettuce) Multicellular green algae (looks like a plant) Lives in marine and brackish water Has flat, blade like leaves called a thallus which is made up of two layers of cells Gametes are free-swimming and a zygote is formed in the water

Ulva Life Cycle Mitosis: 1 cell becoming 2 equal diploid cells Meiosis: 1 cell becoming 4 haploid cells (gametes)

Lichens Can be formed by a symbiotic relationship between green algae and a fungus The fungus provides the algae with water and minerals that it absorbs from whatever it is growing on and protects the algae by retaining water and serving as a larger capture area for minerals and nutrients

The algal cells uses minerals and water to make food for the fungus and itself Stained slide

Youtube http://www.youtube.com/watch?v=OHRPfkCeXHg&feature=related killer algae #1 http://www.youtube.com/watch?v=gE3d3o1nvt8&feature=related killer algae #2 http://www.youtube.com/watch?v=hkrWSpNY2B4&feature=PlayList&p=D6BA6B6F9097A4F5&playnext=1&playnext_from=PL&index=11 killer algae #3 http://www.youtube.com/watch?v=9PMUHQo2qaU&feature=PlayList&p=D6BA6B6F9097A4F5&index=12 killer algae #4 http://www.youtube.com/watch?v=EsNJKvNhCP8&feature=PlayList&p=D6BA6B6F9097A4F5&index=13 killer algae #5 http://www.youtube.com/watch?v=b8ugGN9lCu0&feature=related volvox http://www.youtube.com/watch?v=NzV_tE75SmA&feature=related chlamydomonas http://www.youtube.com/watch?v=LsU6xRvGl8k algae lady on Vancouver Island http://www.youtube.com/watch?v=8edk6nGMwMs&feature=PlayList&p=E189ADC6E5940F0F&playnext=1&playnext_from=PL&index=2 elodea cytoplasmic streaming– an aquatic angiosperm not an algae http://www.youtube.com/watch?v=F_CRQYw9nvc&feature=PlayList&p=D6BA6B6F9097A4F5&playnext=1&playnext_from=PL&index=1 algae as a biofuel http://www.youtube.com/watch?v=1MeIgaRfyD4 algae as biofuel http://www.youtube.com/watch?v=YO3Gg3YfJ84&feature=related algal blooms are centre stage

Red Algae - Rhodophyta Red algae are red because of the presence of the pigment phycoerythrin; this pigment reflects red light and absorbs blue light. Because blue light penetrates water to a greater depth than light of longer wavelengths, these pigments allow red algae to photosynthesize and live at somewhat greater depths than most other "algae".

Importance of red algae Nori sushi high vitamin and protein content relative simplicity of cultivation, which began in Japan more than 300 years ago. Agar Bacterial growth medium Carrageenan -food additive/thickener

Importance of red algae important in the formation of tropical reefs, in some Pacific atolls, red algae have contributed far more to reef structure than other organisms, even more than corals. called coralline algae, because they secrete a hard shell of carbonate around themselves, in much the same way that corals do.

Nori – red algae used for food/sushi

Agar agar – red algae used for food and bacterial cultures

Carrageenan – red algae used as a food additive and thickener

Coralline algae

Brown algae - phaeophyta May reach over 30 meters in length. Almost all are marine. Pigments chlorophyll c and fucoxanthin.

Brown algae - phaeophyta Blades (analogous to leaves) branch from the stipe, or stalk Receptacles form on the surface of the blades structures in which the gametes are produced.

Sargassum – brown algae Pelagic (free-floating)

Fucus – also called rockweed Attached to rocks via stipes

Youtube http://www.youtube.com/watch?v=jcWYAnmm-QE&feature=related kelp forest http://www.youtube.com/watch?v=v_aSl3iL7rM cousteau kelp forest

5 Really Bad Algae Jokes….. Why did the algae and the fungus get married? They took a lichen to each other. Why do many algae couples drift apart? They prefer planktonic relationships. Why couldn't the algae keep a girlfriend? He wasn't a fungi. Why did the algae get pulled over on his way to the pond? He was chloro-plastered. Why did the algae fail math? He divided when multiplying. He didn’t know algae-bra.