Transcript Chapter 35
A phylogeny of Kingdom Protista Biology 2: Form and Function Overview • Highly diverse, likely polyphyletic group • Classification based on morphology (presence/absence of flagella/cilia), pigmentation, types of mitosis, mitochondrial design, molecular genetics, modes of nutrition and locomotion, and presence of body armor • Occupy diverse ecological habitats and include photosynthesizers, heterotrophs, decomposers, parasites and pathogens • Differences between some groups are great enough to indicate separate endosymbiotic events Heterotrophs with no permanent locomotor apparatus • Characterized by locomotion through pseudopodia • Actinopodia and Foraminifera are armored with silica tests - pseudopodia extrude through pores in the glassy coating • Rhizopoda includes the classic protist species Amoeba Rhizopoda Actinopodia Foraminifera Flagellate protists • Includes: • Pyrrhophyta (dinoflagellates), photosynthetic (chlorophyll a, c, carotenoids) • Euglenophyta (euglenoids), photosynthetic (chlorophyll a, b, carotenoids) • Zoomastigina (includes choanoflagellates, probably the ancestor of Kingdom Animalia) Algae • Both unicellular and multicellular (seaweed) forms. • Each phyla obtained chloroplasts in separate endosymbiotic events – Chlorophyta (green alga), chlorophyll a, b, carotenoids – Rhodophyta (red alga), chlorophyll a, carotenoids, phycobilins – Phaeophyta (brown alga) chlorophyll a, c, carotenoids Diatoms (Chrysophyta) • Classified based on radial or bilateral symmetry of silica shell • Important component of phytoplankton responsible for high proportion of global productivity • Unique forms of sexual and asexual reproduction Ciliaphora (Ciliates) • Covered in hair-like cilia • Tough outer pellicle • Specialized vacuoles for ingestion and water balance regulation • Organelle systems • Includes Paramecium Apicomplexa (Sporozoans) • Complex life cycles • Many are parasitic or pathenogenic (e.g., Plasmodium [malaria]) • Thick walled cysts make many sporozoans resistant to drug treatments Slime molds • Acrasiomycota (cellular slime molds) • Myxomycota (plasmodial slime molds) • Oomycota