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?Is slime mold smarter than Japan's railway engineers?  check it out!

Slime Mold Life Cycle

Psychedelic slime mold video:

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

Living Specimens Porphyridium

Preserved specimens Chondrus crispus Porphyra coralline algae

Porphyra life cycle both 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 18 th 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 Chlamydomonas Pandorina Volvox Pediastrum Closterium

Volvox

Preserved Specimens Ulva Chara

Table 4: Representative Green Algae (pg. 72) NameBody FormCharacteristics SpirogyraFilamentous UlvaLeaf like CharaBranched ChlamydomonasUnicellular flagellate PandorinaAggregate VolvoxColony (flagellate) PediastrumNon-motile colony ClosteriumNon-motile single celled

Start filling out Table 5 Comparison of protists studied last week and this week