Protists (CHPTR 8 28) PDF

CHPTR 8 28 PROTISTS Pre-reading assignment What is the difference between prokaryotes and eukaryotes? What is a protist? Are algae aquatic plants? What is a distinctive feature of ciliates? Define endosymbiosis. EUKARYOTE CHARACTERISTICS Membrane bound nucleus and or...

CHPTR 8 28 PROTISTS Pre-reading assignment What is the difference between prokaryotes and eukaryotes? What is a protist? Are algae aquatic plants? What is a distinctive feature of ciliates? Define endosymbiosis. EUKARYOTE CHARACTERISTICS Membrane bound nucleus and organelles Cytoskeleton present Flexible membrane ENDOSYMBIOSIS: A TYPE OF SYMBIOSIS WHERE ONE ORGANISM LIVES INSIDE THE OTHER, THE TWO BEHAVING LIKE A SINGLE ORGANISM ORIGIN OF TRUE NUCLEUS AND ENDOMEMBRANE SYSTEM ENDOSYMBIOSIS- ORIGIN OF MITOCHONDRIA AND CHLOROPLAST Primary and Secondary Endosymbiosis Primary HOST Endosymbiosis: A symbiont is engulfed by a host SYMBIONT 2. VESICULAR 3. PLASMA MEMBRANE OF MEMBRANE OF 1ST HOST 1ST HOST 1. PLASMA 4. VESICULA MEMBRANE OF HOST 1ST SYMBIONT MEMBRANE 2ND HOST Secondary Endosymbiosis: A host engulfs a symbiont that has already engulfed another symbiont. SYMBIONT Diversity of plastids produced by endosymbiosis Plastid Stramenopiles Secondary endosymbiosis Membranes are represented as dark lines in the cell. Red alga Cyanobacterium 1 2 3 Alveolates Primary endosymbiosis Plastid Secondary Nucleus endosymbiosis One of these Heterotrophic membranes Euglenids eukaryote was lost in red and green algal descendants. Secondary endosymbiosis Green alga © 2017 Pearson Education, Inc. Chlorarachniophytes Primary and Secondary Endosymbiosis Primary Endosymbiosis: A symbiont is engulfed by a host and the chloroplast formed thus has two membranes (vesicular membrane of the host and plasma membrane of the symbiont) Secondary Endosymbiosis: A host engulfs a symbiont that has already engulfed a symbiont. The organelle formed thus has 4 membranes (vesicular membrane of the 2nd host, plasma membrane of the 1st host, and the two membranes of the chloroplast) EVIDENCE FOR ENDOSYMBIOTIC THEORY Many symbiotic relationships in nature Mitochondria and chloroplasts have their own DNA Mitochondria have their own small ribosomes Mitochondria and chloroplasts replicate by binary fission like bacteria  Key evidence supporting an endosymbiotic origin of mitochondria and plastids: Inner membranes of both organelles are similar to plasma membranes of living bacteria DNA structure and cell division are similar to bacteria Both organelles transcribe and translate their own DNA Ribosomes are more similar to bacterial than to eukaryotic ribosomes © 2017 Pearson Education, Inc. MITOSIS EVOLVED IN EUKARYOTES BINARY FISSION MITOSIS In prokaryotes In eukaryotes No mitotic apparatus Mitotic apparatus present Process is faster Process takes longer No distinct phases Has 4 distinct phases PROTIST CHARACTERISTICS Cell surface Locomotion Nutrition Reproduction  AMOEBA CELL SURFACE Just a plasma membrane DINOFLAGELLATES Extra cellular matrix hardened with silica Cell surface becomes hard to form a cyst LOCOMOTION DINOFLAGEL LATE Flagella NOCTILUCA Cilia CILIATE PARAMECIUM Pseudopodia : lobopodia FORAMINIFE filopodia RAN axopodia AMOEBA RADIOLARIA N NUTRITION ULVA PHOTOTROPHS (GREE N (PHOTOSYNTHETIC ALGA) AUTOTROPHS) HETEROTROPHIC PHAGOTROPHS AMOEB EUGLENA A (EUGLENOZO AN HETEROTROPHIC EUGLENID) OSMOTROPH TRYPANOSOM A (EUGLENOZO MIXOTROPHS AN KINETOPLAST ID) REPRODUCTION Plasmodium ASEXUAL REPRODUCTION ASEXUAL SCHIZOGONY ASEXUAL BUDDING Toxoplasma gondii SEXUAL REPRODUCTION 4 SUPER GROUPS OF EUKARYOTES Excavata 5 µm Archaeplastida 20 µm 25 µm Diplomonads Excavata Parabasalids Euglenozoans Stramenopiles Diatoms Golden algae Brown algae SAR 50 µm Unikonta Dinoflagellates Alveolates Apicomplexans SAR Ciliates Radiolarians Rhizarians Forams Cercozoans 100 µm Red algae Archaeplastida algae Chlorophytes Green Charophytes Plants 100 µm Amoebozoans Opisthokonts Slime molds Tubulinids Entamoebas Unikonta Nucleariids Fungi Choanoflagellates Animals © 2017 Pearson Education, Inc.  TA EXCAVA Diplomonads Parabasalids Euglenozoans LES STRAMENOPI Excavata Diatoms Golden algae Brown algae SAR Dinoflagellates ES ALVEOLAT Apicomplexans Ciliates SAR Radiolarians Forams A RHIZARI Cercozoans DA PLASTI E ARCHA Red algae 100 µm Archaeplastida GREEN Chlorophytes ALGAE Charophytes PLANTS OA AMOEBOZ Slime molds A UNIKONT Tubulinids Unikonta Entamoebas Nucleariids A OPISTHOKONT FUNGI Choanoflagellates ANIMALS © 2017 Pearson Education, Inc. SUPER GROUP EXCAVATA- Phy Euglenozoa EUGLENA 3. 5. 1. 8. 7. 9 4.. 6. 2. PARASITIC EUGLENOZOAN Triatomine bug (kissing bug)- insect vector for Trypanosoma cruzi SUPER GROUP SAR ALVEOLATA- have alveoli, a series of flattened sacs under plasma membrane STRAMENOPILA- have fine hair like structures on their flagella SUPER GROUP SAR Super Phy STRAMENOPILA Giant kelp 1. BROWN ALGA Marine Multicellular Macroscopic BLADE STIPE HOLDFA ST HAPLODIPLONTIC LIFE Haploid (n) CYCLE Diploid (2n) Sporangia MEIOSIS 10 cm Sporophyte (2n) Zoospore Female Developing sporophyte Gameto- phytes Zygote (n) Mature female (2n) gametophyte Egg Male (n) FERTILIZATION Sperm © 2017 Pearson Education, Inc. BASIC HAPLODIPLONTIC CYCLE SPOROPHYTE 2n ZYGOTE GENERATIO --------------------------------------------------------------------------------------- N ------------- n GENERATIO N SPORE. SPORE GAMETE. GAMETOPHYTE GAMETE. GAMETOPHYTE PLASMODIUM Inside mosquito Inside human LIFE CYCLE Merozoite Sporozoites (n) Liver Liver cell Apex Oocyst MEIOSIS Red blood Merozoite 0.5 µm (n) cell Red Zygote blood (2n) cells FERTILIZATION Gametes Game- tocytes Haploid (n) (n) Diploid (2n) © 2017 Pearson Education, Inc. SUPER GROUP SAR PHY CILIOPHORA Oral groove Contractile vacuole Cell mouth 50 µm Micronucleus Macronucleus LIFE CYCLE OF PARAMECIUM (b) Conjugation and reproduction 3 micronuclei degenerate, the remaining undergoes mitosis Compatible Conjugation mates MEIOSIS Asexual reproduction micronuclei are swappe Diploid Four Haploid micronucleus micronuclei Diploid The original macro- Paramecia separate micronucleus nucleus disintegrates. MICRO- NUCLEAR Conjugation FUSION Asexual 4 micro reproduction nuclei become macro nuclei © 2017 Pearson Education, Inc. SUPER GROUP ARCHAEPLASTIDA Phy RHODOPHYTA Some microscopic, some macroscopic Red algae Accessory photosynthetic pigments (phycoerythrin, phycocyanin, allophycocyanin) Agar agar made from Gelidium Agar agar red alga is a vegetarian substitute for gelatin. Nori- seaweed used to wrap sushi is red alga Porphyra. SUPER GROUP ARCHAEPLASTIDA Phy CHLOROPHYTA Green algae Unicellular- Chlamydomonas Colonial- Volvox Multicellular- Ulva SUPER GROUP ARCHAEPLASTIDA Phy Chlorophyta Chlamydomonas Unicellular Gamete (n) Zoospore Autotrophic Mature cell 2 flagella at anterior ASEXUAL REPRODUC (n) FERTILIZATION SEXUAL end TION REPRODUCTION Zygote (2n) MEIOSIS Haploid (n) Diploid (2n) SUPER GROUP ARCHAEPLASTIDA Phy CHAROPHYTA Microscopic- Coleochaetes Macroscopic- Charales Both have flagellated sperm and a non-motile egg Grow around freshwater ponds and marshes LAND PLANTS EVOLVED FROM CHAROPHYTES Super Group Unikonta include protists that are closely related to fungi and animals AMOEBOZOA SLIME MOLDS UNIKONTA A OPISTHOKONT CHANOFLAGEL LATES AMOEBOZOA (THE AMOEBAS) PLASMODIAL SLIME MOLDS CELLULAR SLIME MOLDS Multinucleate mass of cytoplasm Aggregation of single amoebas Nuclei are 2n Nuclei are n Asexual reproduction Asexual reproduction When moisture or food is lacking, they When food or moisture is lacking, the develop sporangia that produce n spores amoebas aggregate to form a slug. This that develop into gametes that fuse to form slug produces n spores which develop into the 2n plasmodium n amoebas. SUPER GROUP OPISTHOKONTA (Fungi, Choanoflagellates, Animals) Unicellular Single flagellum Colonial; resemble freshwater sponges which are animals