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Kelp/Brown Algae. By: Marie-Louise Posch. Kelp. Kelp – general term for 124 species of brown algae. Classified in the Kingdom Chromista or Protista. http://www.youtube.com/watch?v=Y9eyK6C9nDA (0:28) http://www.youtube.com/watch?v=naYu4m3b6cw (3:04). Kelp Forest. Structure.
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Kelp/Brown Algae By: Marie-Louise Posch
Kelp • Kelp – general term for 124 species of brown algae. • Classified in the Kingdom Chromista or Protista. • http://www.youtube.com/watch?v=Y9eyK6C9nDA (0:28) • http://www.youtube.com/watch?v=naYu4m3b6cw (3:04) Kelp Forest
Structure • The kelp plant has three parts: the blade (the leaf-like structure), the stipe (the stem-like structure), and the holdfast (root-like structure) • Holdfasts grip substrates • Blades are buoyed by air bladders • Do not dry up at low tide because cell walls contain a mucilaginous, water retaining material Kelp
Function • Kelp grows in forests, which can be made of more than one species • Provides habitat and food for marine life including fish, invertebrates, marine mammals, and birds • A good source of protein, iodine, and iron • Protects the body from heavy toxic metals • The sodium alginate in kelp helps prevent absorption of radioactive strontium 90
Brown Algae • The largest, most complex type of algae • Contains chlorophyll a and c • The pigment fucoxanthin gives it its color • Air bladders help the blades float to allow for maximum sunlight absorption. Brown Algae
Structure • Have chloroplasts surrounded by four membranes, suggesting an origin between basal eukaryotes and another eukaryote • Develop into multicellular forms with differentiated tissues, but they reproduce by flagellate spores and gametes Brown Algae
Function • Food source for fish, gastropods, and sea urchins. • Benthic (bottom-dwelling) organisms benefit when pieces of it sink to the sea floor • Common uses include food thickeners, stabilizers, and fillers. Also used in pharmaceuticals • Contains chemicals called alginates that are used to thicken certain products like toothpaste and ice cream.
Review Questions • What are the three parts of a kelp plant? • blade, stipe, and holdfast • What is the function of an air bladder? • help the blades float to allow for sunlight absorption • Name some common uses of brown algae by people • food thickeners, stabilizers, pharmaceuticals, and fillers • Name two ways kelp benefits marine life? • Food source and habitat • How does brown algae reproduce? • by flagellate spores and gametes • What is unique about the structure of brown algae? • Have chloroplasts surrounded by four membranes