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Protists -the simplest eukaryotes Chapter 22 I have loved England, dearly and deeply, Since that first morning, shining and pure, The white cliffs of Dover I saw rising steeply Out of the sea that once made her secure. I had no thought then of husband or lover, I was a traveler, the guest of a week; Yet when they pointed 'the white cliffs of Dover', Startled I found there were tears on my cheek. I have loved England, and still as a stranger, Here is my home and I still am alone. Now in her hour of trial and danger, Only the English are really her own. From The White Cliffs of Dover by Alice Duer Miller Characteristics of Kingdom Protista Eukaryotic More than one chromosome consisting of DNA + protein Divide through mitosis and meiosis Mostly single celled What they are NOT Protists have traditionally been grouped together more because what they are NOT than what they ARE. They do not fit into any other eukaryotic kingdom (fungi, plant, animal) Through genetic analysis, the relationship between these organisms is just becoming clear. Seven different monophyletic protistan groups: Parabasalids and Diplomonads Euglenoids and Kinetoplastids Forams and Radiolarians Amoebozoans Red Algae Green Algae Stramenophiles and Alveolates (BIG group!) Parabasalids and Diplomonads Protozoa- single celled, predatory, parasitic member of the protistan kingdom Evolutionarily far removed from animals Heterotrophic flagellates Few mitochondria because of anaerobic or oxygen poor habitats Highlighted Speciesparabasalid Trichomonas vaginalis * epithelial linings of reproductive organs * sucks out nutrients * can be transmitted to fetus during childbirth Highlighted Speciesdiplomonad Giardia lamblia * very simple internal structure * intestinal parasite of humans, cattle and wild animals * leaves sucking imprints on inside of intestine and can result in giardiasis Euglenoids and Kinetoplastids Flagella! Some autotrophic and some heterotrophic Euglenoids have contractile vacuoles Kinetoplastids have huge mitochondria Most kinetoplastids are parasites Highlighted SpeciesEuglenoid Euglena *photosynthetic * contractile vacuole * reproduces through binary fission Highlighted SpeciesKinetoplastid Trypanosoma brucei * causes African sleeping sickness * Tsetse fly carries T. brucei * Lodges in brain of host. * Causes listlessness, drowsiness and mental deterioration Foraminiferans and Radiolarians Heterotrophs Amoeba-like organisms inside perforated shells Pseudopods extend through hundreds of holes in the shells Plankton- microscopic organisms that drift or swim weakly in water. Amoebozoans Most closely related to fungi and animals Mostly single celled but can display communal behavior and some cell differentiation No cell wall or shell Dynamic changes in shape Amoebas and slime molds Highlighted SpeciesAmoebozoa Entamoeba histolytica *can infect people who drink contaminated water * live in human intestinal tract and eat bacteria and epithelial cells * causes amoebic dysentery * shares some genes with some prokaryotes * kills 100,000 people/year Amoebozoa Highlighted SpeciesSlime Molds Plasmodial slime molds (175 species) * social amoebas * found in forests; on wood or ground cover Red Algae (Rhodophyta) Live in warm marine climates Photoautotrophic and contain phycobilins (absorb green and blue-green light) Although single celled, most show multicellular growth Used as agar, in paints, sushi, dairy foods Rhodophyta Green Algae (Chlorophyta) Closest relatives of land plants Mostly freshwater aquatic but some marine Single celled and multicellular growth Volvox, Ulva, Chlamydomonas THE BIG GROUP: the alveolates and stramenopiles Dinoflagellates Ciliates Oomycotes Diatoms Chrysophytes Phaeophyta