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2. Resources Chapter Presentation Visual Concepts Transparencies Standardized Test Prep

3. Chapter 25 Protists Table of Contents Section 1 Characteristics of Protists Section 2 Animal-like Protists Section 3 Plantlike and Funguslike Protists Section 4 Protists and Humans

4. Section 1 Characteristics of Protists Chapter 25 Objectives • Define protist. • Describe a hypothesis for the origin of eukaryotic cells. • Explain how protists are classified. • Describe the two major ways by which protists obtain energy. • List three structures protists use for movement. • Describe how protists reproduce.

5. Section 1 Characteristics of Protists Chapter 25 A Diverse Group of Eukaryotes • Protists are unicellular or simple multicellular eukaryotic organisms that are not plants, fungi, or animals. • Made of eukaryotic cells, containing nucleus and other organelles

6. Section 1 Characteristics of Protists Chapter 25 Characteristics of Protists Click below to watch the Visual Concept. Visual Concept

7. Section 1 Characteristics of Protists Chapter 25 A Diverse Group of Eukaryotes, continued • The First Eukaryotes • Evidence suggests that the first protists arose from endosymbiotic prokaryotes.

8. Section 1 Characteristics of Protists Chapter 25 Origin of Eukaryotic Cells Click below to watch the Visual Concept. Visual Concept

9. Section 1 Characteristics of Protists Chapter 25 Classification • Protists are classified by the characteristics that make them fungus-like, plant-like, or animal-like.

10. Section 1 Characteristics of Protists Chapter 25 Characteristics • Unicellular and Multicellular • Most protists are unicellular, but some form large, multicellular bodies.

11. Section 1 Characteristics of Protists Chapter 25 Comparing Organisms that are Unicellular and Multicellular Click below to watch the Visual Concept. Visual Concept

12. Section 1 Characteristics of Protists Chapter 25 Characteristics, continued • Nutrition • Many protists are autotrophs, organisms that make their own food. • Phototrophs – use sunlight for energy to make food • Chemotrophs- use chemicals for energy to make food • Other protists are heterotrophs, organisms that must get their food by eating other organisms or their byproducts.

13. Section 1 Characteristics of Protists Chapter 25 Characteristics,continued • Motility • Protists use flagella, cilia, or pseudopodia for locomotion.

14. Section 1 Characteristics of Protists Chapter 25 Reproduction • Many protists reproduce asexually… • Binary fission:asexual reproduction where a single cell splits into two cells • Multiple fission:a form of cell division that produces more than two offspring from one cell

15. Section 1 Characteristics of Protists Chapter 25 Reproduction (cont…) • Sexual Reproduction… • Offspring are genetically different • Conjugation:two individuals join and exchange genetic material stored in a small second nucleus, then the cell divides into four offspring • Some protists do this during stressful environmental conditions

16. Section 1 Characteristics of Protists Chapter 25 Protist Reproduction

17. Section 2 Animal-like Protists Chapter 25 Objectives • Discussthe key characteristics of Protozoa, Ciliophora, Sarcomastigophora, and Apicomplexa. • Describehow protozoa use pseudopodia to move and to capture food. • Explainhow ciliates move and reproduce. • Describehow mastigophorans move and capture food. • Describethe role of apicomplexans in disease.

18. Section 2 Animal-like Protists Chapter 25 Phylum Protozoa • Animal-like protists can be found in the phylum Protozoa. • Protozoa use large, rounded, cytoplasmic extensions called pseudopodia forboth movement and feeding.

19. Section 2 Animal-like Protists Chapter 25 Phylum Protozoa, continued • Protozoan Diversity • Protozoans include organisms that inhabit the oceans, lakes, soil and even the human intestines. • Example - amoeba

20. Section 2 Animal-like Protists Chapter 25 Phylum Ciliophora Characteristics • Animal-like protists include the phylumCiliophora. • Ciliates move using cilia, which are short, hairlike, cytoplasmic projections that line the cell membrane.

21. Section 2 Animal-like Protists Chapter 25 Paramecium

22. Section 2 Animal-like Protists Chapter 25 Phylum Ciliophora Characteristics (cont.) • Ciliates have the most elaborate organelles, (ex. oral groove, mouth pore, gullet, food and contractile vacuoles, & anal pore) • including two types of nuclei. • Large macronucleus – contains multiple copies of DNA • Directs cell metabolism & development • Smaller micronucleus – exchanges genetic material (DNA) during conjugation

23. Section 2 Animal-like Protists Chapter 25 Feeding Habits of a Ciliate Click below to watch the Visual Concept. Visual Concept

24. Section 2 Animal-like Protists Chapter 25 Phylum Ciliophora, continued • Reproduction • Ciliates reproduce asexually by binary fission and sexually by conjugation. • Example: paramecium

25. Section 2 Animal-like Protists Chapter 25 Phylum Sarcomastigophora • Animal-like protists include the phyla Protozoa,Sarcomastigophora. • For locomotion, sarcomastigophorans use flagella. • Example: Trypanosomes • These organisms cause African Sleeping Sickness • Spread by tsetse flies

26. Section 2 Animal-like Protists Chapter 25 Phylum Apicomplexa • Animal-like protists include the phylaApicomplexa. • These protists are animal parasites. • Example: Plasmodium; these cause malaria

27. Section 2 Animal-like Protists Chapter 25 Types of Animal-like Protists Click below to watch the Visual Concept. Visual Concept

28. Section 3 Plantlike and Funguslike Protists Chapter 25 Objectives • Describefour main body forms of algae. • List the common name for each of the seven phyla of plantlike protists. • Explainhow green algae and plants are similar. • Describefour phyla of funguslike protists. • Compareplasmodial slime molds, cellular slime molds, and water molds.

29. Section 3 Plantlike and Funguslike Protists Chapter 25 Characteristics of Algae • Algae are autotrophic protists • can be unicellular, colonial, filamentous, or multicellular. • Found in both fresh & salt water • Some have structures to help them anchor, reproduce, & move • Seven phyla of plantlike protists are Chlorophyta, Phaeophyta, Rhodophyta, Bacillariophyta, Dinoflagellata, Chrysophyta, and Euglenophyta.

30. Section 3 Plantlike and Funguslike Protists Chapter 25 Plantlike Protists • Phylum Chlorophyta (Green Algae) • The phylum Chlorophyta contains more than 17,000 identified species of protists called green algae. • Both green algae and plants have chlorophylls and accessory pigments, store food as starch, and have cell walls made up of cellulose.

31. Section 3 Plantlike and Funguslike Protists Chapter 25 Plantlike Protists, continued • Phylum Phaeophyta (Brown Algae) • The phylum Phaeophyta includes approximately 1,500 species of multicellular (most plant like) organisms called brown algae. • Brown algae are mostly marine organisms, and they include plantlike seaweeds and kelps.

32. Section 3 Plantlike and Funguslike Protists Chapter 25 Plantlike Protists, continued • Phylum Rhodophyta (Red Algae) • The 4,000 species in the phylum Rhodophyta are known as red algae. • A few species of red algae live in fresh water or on land, but most red algae are marine seaweeds.

33. Section 3 Plantlike and Funguslike Protists Chapter 25 Plantlike Protists, continued • Phylum Bacillariophyta (Diatoms) • The phylum Bacillariophyta contains as many as 100,000 species of unicellular protists called diatoms. • Have silica cells walls called shells that fit together in two pieces • Abundant component of phytoplankton and major producers

34. Section 3 Plantlike and Funguslike Protists Chapter 25 Plantlike Protists, continued • Phylum Dinoflagellata (Dinoflagellates) • More than 2,000 species of organisms called dinoflagellates make up the phylum Dinoflagellata. • Some species of dinoflagellates, such as those in genus Noctiluca, can produce bioluminescence, a display of sparkling light often seen in ocean water at night.

35. Section 3 Plantlike and Funguslike Protists Chapter 25 Plantlike Protists, continued • Phylum Chrysophyta (Golden Algae) • The phylum Chrysophyta contains about 1,000 species of golden algae. Most golden algae live in fresh water, but a few species are found in marine environments.

36. Section 3 Plantlike and Funguslike Protists Chapter 25 Plantlike Protists, continued • Phylum Euglenophyta (Euglenoids) • The phylum Euglenophyta contains about 1,000 species of flagellated unicellular algae called euglenoids. • Euglenoids are both plantlike and animal-like. Many are autotrophic, like plants, but they lack a cell wall and are highly motile, like animals.

37. Section 3 Plantlike and Funguslike Protists Chapter 25 Structure of Euglena

38. Section 3 Plantlike and Funguslike Protists Chapter 25 Funguslike Protists • Biologists recognize two groups of funguslike protists: slime molds and water molds.

39. Section 3 Plantlike and Funguslike Protists Chapter 25 Funguslike Protists, continued • Phylum Myxomycota (Plasmodial Slime Molds) • Plasmodial slime moldsare multinucleate. • Technically one cell because only 1 cell membrane • As the plasmodium creeps along the forest floor by cytoplasmic streaming, it consumes decaying leaves and other debris by phagocytosis.

40. Section 3 Plantlike and Funguslike Protists Chapter 25 Funguslike Protists, continued • Phylum Dictyostelida (Cellular Slime Mold) • Cellular slime moldslive as individual haploid cells that move about like amoebas. • Each cell moves as an independent organism, creeping over the ground or swimming in fresh water and ingesting food.

41. Section 3 Plantlike and Funguslike Protists Chapter 25 Funguslike Protists, continued • Phylum Oomycota (Water Molds) • Water molds are composed of branching filaments and many of this phylum are parasitic.

42. Section 3 Plantlike and Funguslike Protists Chapter 25 Funguslike Protists, continued • Phylum Chytridiomycota (Water Molds) • Members of phylum Chytridiomycota, or the chytrids, are primarily aquatic protists characterized by gametes and zoospores with a single, posterior flagellum.

43. Section 4 Protists and Humans Chapter 25 Objectives • Statefour environmental roles of protists. • Describealgal blooms and red tides and their impact. • Statean important role for protists in research. • Lista use of protists as food and three uses of protist byproducts. • Describefour protist-caused diseases.

44. Section 4 Protists and Humans Chapter 25 Protists in the Environment • Photosynthetic protists are foundation of many food chains and produce large amounts of oxygen • Play important role in carbon cycle and form many symbiotic relationships (coral, lichen) • Recycle materials

45. Section 4 Protists and Humans Chapter 25 Protists in the Environment, continued • Algal bloomscan lead to the depletion of oxygen in water. • One cause is high nutrient concentrations in water • Red tides (type of algal bloom) produce harmful toxins.

46. Section 4 Protists and Humans Chapter 25 Protists in Research • Research on protists has helped biologists understand a number of fundamental cellular functions, such as leukocyte movement (chemotaxis).

47. Section 4 Protists and Humans Chapter 25 Protists in Industry • Protists as Food • For thousands of years, humans have been collecting seaweeds for food.

48. Section 4 Protists and Humans Chapter 25 Protists in Industry, continued • Protist Byproducts • Protists provide important byproducts, such as alginate, carrageenan, and agar. • These are used in cosmetics, food products, textiles, medical dressings • Diatomaceous earth is used in detergents, paint removers, toothpaste, and as a natural insecticide

49. Section 4 Protists and Humans Chapter 25 Protists and Health • Parasitic protists cause malaria, giardiasis, amebiasis, cryptosporidiosis, trichomoniasis, and African sleeping sickness in humans. • Giardiasis • severe diarrhea and intestinal cramps • get from drinking contaminated water • Sleeping sickness • Protist that causes it spread by tsetse fly

50. Section 4 Protists and Humans Chapter 25 Protists and Health • Malaria • Parasitic protists in the genus Plasmodium cause malaria, which is characterized by severe chills, headache, fever, and fatigue. • Each year, nearly 3 million people die from malaria.