Lab 18: Protists (Fall 2024) - Lab Manual/Notes PDF

Lab 18: Protists Fall 2024, 13.1-13.4 Upcoming Quiz 4 (Nov. 25) (Lab 16 ~ 18) Lab report (Final Draft) (Dec. 2 11:59PM) ○ Update your draft in real time on Google Drive ○ Haven’t submitted the first draft  Send me the final draft via my email First! Bacteriology Results 1...

Lab 18: Protists Fall 2024, 13.1-13.4 Upcoming Quiz 4 (Nov. 25) (Lab 16 ~ 18) Lab report (Final Draft) (Dec. 2 11:59PM) ○ Update your draft in real time on Google Drive ○ Haven’t submitted the first draft  Send me the final draft via my email First! Bacteriology Results 12.4A (antibiotics) 12.4B (antiseptics/disinfectants): using a mm ruler, measure the zones of inhibition around the disks on your plates (record in your notebook) First! Bacteriology Results 12.3A and B: using a stereoscopic microscope, look at the colonies that developed on your plates, and characterize them according to the following criteria. What is the overall shape? Are there any surface characteristics you can identify? How would you characterize the margins? Additionally: What is the Opacity? (ie: opaque, translucent, transparent, or combination) Is there distinct pigmentation? Phylogenetics Monophyletic: a group of organisms, Polyphyletic: a Paraphyletic: a group of all descended from a common ancestor group of organisms organisms descended (and the common ancestor): a clade. that doesn’t include from a common ancestor a most recent but that doesn’t include all common descendants. common ancestor. Models of evolutionary history and relationships among or within groups of organisms Protists The most diverse group of eukaryotes Classified by supergroups and clades Paraphyletic group: the default group for all eukaryotes that are not land plants, animals, or fungi Protist taxonomy: supergroups and clades Currently four main Supergroups: Excavata, SAR, Unikonta, Archaeplastida, which house seven (overall) main clades. Protists: diversity Protists employ a variety of life strategies: Autotrophs: contain chloroplasts and can synthesize their own food through photosynthesis (eg: algae) Heterotrophs: consume other organisms ○ Protozoans: get their food through phagocytosis (similar to animals) ○ Slime molds: get their food by absorption (similar to fungi) Mixotrophs: obtain nutrition through both photosynthesis and consuming other organisms Protists also inhabitat a variety of environments: Protists also employ a variety of Freshwater reproductive strategies: Saltwater, and Sexual and Parasitic species. Asexual  We will observe Protist taxonomy: Clades MAIN EXAMPLE with: Trypanosoma Prepared slide Euglenozoa (Supergroup: Excavata) - Paramecia Prepared slide example Trypanosoma Diatoms Prepared slide Stramenopila (Supergroup: SAR) - Sargassum (brown examples Diatoms, Brown Algae algae) Demonstration Alveolata (Supergroup: SAR) - example Forams Prepared slide Paramecia Radiolarians Prepared slide Rhizarians (Supergroup: SAR) - examples Amoeba Prepared slide Foraminiferans & Radiolarians Amoebozoans (Supergroup Unikonta) - Polysiphonia (red algae) Demonstration examples Amoeba, Physarum Chlorophyta (Supergroup: Archaeplastida) Spirogyra (green algae) Picture - examples Green algae: Spirogyra, Ulva Ulva (green algae) Demonstration Rhodophyta (Supergroup: Archaeplastida) Dinoflagellates Not in lab – example: Red algae Physarum (slime mold) Not in lab Chara (green algae) Not in lab Exercise 13.1: Supergroup excavata, clade euglenozoa Trypanosoma: unicellular parasite found in rat blood Clade Euglenozoa and is transmitted by fleas. Supergroup Excavata Very long and thin with a flagella joined to its the length via an undulating membrane (helps Mode of Heterotrophs, Nutrition autotrophs, parasitic them move through viscous blood) Habitat Freshwater, saltwater, parasitic Distinguishing Primitive red feature eyespot, Spiral or crystalline rod inside their flagella Example Trypanosoma, Euglena Trypanosoma, in rat blood 100X Trypanosoma, in rat blood 400X 13.2- SAR: clade Stramenopila (eg: diatoms). Diatoms Clade Stramenopila Unicellular, colonial, or aggregate algae. Supergroup SAR Planktonic free floating in both freshwater and marine environments. Mode of Most are autotrophs Generate 20% of Earth’s oxygen annually. Nutrition Are nearly 50% of organic material (OM) in Habitat Freshwater, saltwater oceans. (marine) Have a two-part, glass-like wall of hydrated Distinguishing 2 flagella in mobile silica in an organic matrix (a “test”): feature stage: Like a petri dish w/overlapping “base and lid” 1 hairy (Stramen = straw, Pilos = hair) Provide protection from predators and 1 smooth. Only observable structure in prepared microscope slides (OM “killed off” during slide Examples Diatoms, brown preparation). algae 13.2- SAR: clade Stramenopila (eg: diatoms). Two body forms: Centric - radial symmetry Pennate - bilateral symmetry and are elongated Contain no flagella most of their life.  Diatoms, 100X Can be unicellular, colonial, or aggregate. Dr. Iwantsch, Fordham University 13.2- SAR: clade Stramenopila (eg: brown algae). Sargassum Longest, fastest-growing algae (autotrophic) Multicellular, large- bodied Most marine (few freshwater) Provide habitat. Color due to carotenoid pigment: fucoxanthin Have root-like holdfasts that attaches to rocks Gas-filled bladders act as floats. 13.2- SAR: clade Alveolata (eg: paramecium). Clade Alveolata Alveolata are Ciliates: large varied group of protists that use cilia to move and feed Supergroup SAR Cilia: hair-like projections that may completely cover Paramecium’s cell surface or be clustered. Mode of Nutrition Autotrophs, Shorter and more numerous than flagella. heterotrophs, Paramecium have large macronuclei and small parasitic micronuclei. Habitat Freshwater, Haploid micronuclei - used during conjugation, saltwater (marine), a sexual process that produces genetic parasitic variation. Conjugation is not reproduction. Paramecium Distinguishing Membrane-bound reproduce by binary fission (asexual, no feature sacs (Alveoli) under plasma exchange of gametes). membrane Use contractile vacuoles in osmoregulation (regulate water balance), pellicle instead of cell Example Paramecium wall. 13.2- SAR: clade Alveolata (eg: paramecium). Paramecium caudatum 40X, 100X, 400X Paramecium video https://www.youtube.com/watch?v=mh7KOtQTXrw 13.2- SAR: clade Rhizarians (eg: foraminifera) Clade Rhizaria Foraminiferans (Forams) Have porous shells called tests. Supergroup SAR Foram tests are: Mode of Nutrition Heterotrophs, ○ Multi-chambered parasitic ○ Made out of calcium carbonate Habitat Saltwater ○ Arranged in a linear or spiral shape (marine), parasitic Distinguishing feature Forams – Threadlike pseudopodia: used for Calcium carbonate shells swimming, test formation, and feeding. Radiolaria – Silica shells Many also have a symbiotic relationship with algae that live in their tests: forams get Examples Foraminifera (Forams), food (glucose, starch, etc) from them, and in Radiolaria return, algae get protection and shelter. Foraminiferans, W.M. 100X Foraminiferans, W.M. 400X 13.2- SAR: clade Rhizarians (eg: radiolarans) They have glass-like tests made of silica, fused into one spherical piece. Radiolarians also have many needle-like pseudopodia, which are supported by bundles of microtubules. Radiolarians eat microorganisms with their pseudopodia through Which other example within the supergroup phagocytosis. SAR also have glass-like, silica shells? 13.2- SAR: clade Rhizarians (eg: radiolarans) They have glass-like tests made of silica, fused into one spherical piece. Radiolarians also have many needle-like pseudopodia, which are supported by bundles of microtubules. Radiolarians eat microorganisms with their pseudopodia through phagocytosis. Diatoms! Radiolarans, W.M. 40X Radiolarans, W.M. 100X Radiolarans, W.M. 400X 13.3- Unikonta, clade Amoebozoa (eg: amoeba) Amoeba Solitary, unicellular Irregular body shape Lack shells (plasma membrane) Heterotrophic Live in freshwater or marine habitats Move using pseudopodia (lobe shaped) Amoeba proteus, W.M. 40X & 100X 13.4: Archaeplastida, clade Chlorophyta (green algae) Clade Chlorophyta Green algae can be: Unicellular, aggregates, colonial, or Supergroup Archaeplastida multicellular (eg: Ulva, Volvox) Mode of Autotrophs Nutrition Motile (mobile) or nonmotile Habitat Freshwater, saltwater (marine) Filamentous (Spirogyra) Distinguishing Contain common features characteristics to land plants: Chlorophylls a & b Starch Cell walls composed of cellulose Flagellated sperm Examples Spirogyra, Ulva Spirogyra- filamentous green alga, 100X  Spirogyra- filamentous green alga, 400X Distinguishing features: Green double helix made of chloroplasts. Cell wall made of cellulose and pectin.  Ulva– Multicellular green algae Ulva Known as “sea lettuce.” Edible seaweed with a multicellular thallus: ○ differentiated into leaf-like blades and ○ root-like holdfasts, which anchor the alga against wave and tidal action. ○ Cell walls contain cellulose and other polysaccharides. 13.4: Archaeplastida, clade Rhodophyta (red algae) Rhodophyta Photosynthetic (autotrophs) Have several pigments: ○ Chlorophyll a (not b) ○ Phycocyanin and Phycoerythrin (characteristic red color ○ Cell walls composed of: agarose and cellulose Can be single-celled, but most are multicellular Lack flagella Outputs Notebook: Labelled sketches of all specimens and structures Fill out table 13.5 for each organism that we studied in class (use this as a study guide!)