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Protists 2. Laboratory 4 BIOL 171. Note: T he PowerPoint in lab will be abridged so you have more time. Please take a few minutes to read this thoroughly. Thanks!. Lab Study E: Amoebozoans. Amoeba proteus
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Protists 2 Laboratory 4 BIOL 171 Note: The PowerPoint in lab will be abridged so you have more time. Please take a few minutes to read this thoroughly. Thanks!
Lab Study E: Amoebozoans Amoeba proteus • Pseudopodia – temporary extensions of amoeboid cells, function in moving and engulfing food
Slime Molds (Mycetozoa) • Protists which use spores to reproduce • Heterotrophic– requires carbon in organic form, cannot manufacture it’s own • Feed using phagocytosis • Suggests they descended from unicellular amoeba-like organisms • Two types: plasmodial and cellular (we will be observing plasmodial type today)
Physarum(slime mold) • Plasmodial stage – vegetative stage that consists of a multinucleate mass of protoplasm (no cell walls), feeds on bacteria as it creeps along the surface of moist logs or dead leaves • Fruiting bodies – reproductive structures that produce spores
Physarum (plasmodial stage) Is slime mold smarter than Japan's railway engineers?check it out!
What is red algae? • Eukaryotic • Photosynthetic • NOT plants • Most are aquatic
Lab Study F: Red Algae (Rhodophyta) • Simplest is single celled, but most have a macroscopic, multicellular body form • Autotrophic(photosynthetic)– manufactures its own organic nutrients from inorganic carbon sources • Contain chlorophyll a and accessory pigments phycocyanin and phycoerythrin • Not all are red! Many green, black, even blue, depending on the depth in the ocean they grow
Preserved specimens Porphyra coralline algae Chondruscrispus
Porphyra life cycleboth sexual and asexual – alternation of generations!
Coralline algae – “living rock” • Extremely important role in the ecology of coral reefs: sea urchins, fish, and mollusks eat them (herbivore enhancement). • Create microhabitats that protect invertebrates from predation. • Cell walls composed of calcium carbonate – this allows it to fossilize • Economic importance: soil conditioners, food additive for livestock, water filtration, medical vermifuge (stopped late in 18th century), preparation of dental bone implants
Economic Uses • Agar – polysaccharide extracted from the cell wall of red algae, used to grow bacteria and fungi • Carrageenan– extracted from red algae cell walls, used to give the texture of thickness and richness to foods such as dairy drinks and soups. • Porphyra(or nori) – seaweed wrappers for sushi, billion-dollar industry!
Lab Study G: Green Algae (Chlorophyta) • unicellular motile and non-motile, colonial, filamentous, and multicellular – GREAT DIVERSITY • Live primarily in freshwater • Share many characteristics with land plants • Storage of starch, presence of chlorophylls a and b, photosynthetic pathways, and organic compounds called flavonoids • Most botanists support the hypothesis that plants evolved from green algae
Living Specimens Volvox Chlamydomonas Pediastrum Closterium Pandorina
Preserved Specimens Ulva Chara
Start filling out Table 5 • Comparison of protistsstudied last week and this week