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

2. 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.

3. Chapter 25 A Diverse Group of Eukaryotes Protists are unicellular or simple multicellular eukaryotic organisms that are not plants, fungi, or animals. Section 1 Characteristics of Protists

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

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

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

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

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

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

10. Chapter 25 Characteristics, continued Nutrition –Many protists are autotrophs, organisms that make their own food. –Other protists are heterotrophs, organisms that must get their food by eating other organisms or their byproducts. Section 1 Characteristics of Protists

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

12. Chapter 25 Reproduction Protists reproduce either asexually, sexually, or both. They reproduce asexually by binary fission or multiple fission. They often reproduce sexually by conjugation. Section 1 Characteristics of Protists

13. Section 2 Animal-like Protists Chapter 25 Objectives Discuss the key characteristics of Protozoa, Ciliophora, Sarcomastigophora, and Apicomplexa. Describe how protozoa use pseudopodia to move and to capture food. Explain how ciliates move and reproduce. Describe how mastigophorans move and capture food. Describe the role of apicomplexans in disease.

14. 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 for both movement and feeding.

15. 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.

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

17. Section 2 Animal-like Protists Chapter 25 Phylum Ciliophora, continued Characteristics –Ciliates have the most elaborate organelles, including two types of nuclei.

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

19. Chapter 25 Phylum Ciliophora, continued Reproduction –Ciliates reproduce asexually by binary fission and sexually by conjugation.

20. Section 2 Animal-like Protists Chapter 25 Phylum Sarcomastigophora Animal-like protists include the phyla Protozoa, Sarcomastigophora. For locomotion, sarcomastigophorans use flagella.

21. Section 2 Animal-like Protists Chapter 25 Phylum Apicomplexa Animal-like protists include the phyla Apicomplexa. These protists are animal parasites.

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

23. Section 3 Plantlike and Funguslike Protists Chapter 25 Objectives Describe four main body forms of algae. List the common name for each of the seven phyla of plantlike protists. Explain how green algae and plants are similar. Describe four phyla of funguslike protists. Compare plasmodial slime molds, cellular slime molds, and water molds.

24. Section 3 Plantlike and Funguslike Protists Chapter 25 Characteristics of Algae Algae can be unicellular, colonial, filamentous, or multicellular. Seven phyla of plantlike protists are Chlorophyta, Phaeophyta, Rhodophyta, Bacillariophyta, Dinoflagellata, Chrysophyta, and Euglenophyta.

25. 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.

26. 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 organisms called brown algae. –Brown algae are mostly marine organisms, and they include plantlike seaweeds and kelps.

27. 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.

28. 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.

29. 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.

30. 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.

31. 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.

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

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

34. Section 3 Plantlike and Funguslike Protists Chapter 25 Funguslike Protists, continued Phylum Myxomycota (Plasmodial Slime Molds) –Plasmodial slime molds are multinucleate. –As the plasmodium creeps along the forest floor by cytoplasmic streaming, it consumes decaying leaves and other debris by phagocytosis.

35. Section 3 Plantlike and Funguslike Protists Chapter 25 Funguslike Protists, continued Phylum Dictyostelida (Cellular Slime Mold) –Cellular slime molds live 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.

36. 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.

37. 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.

38. Section 4 Protists and Humans Chapter 25 Objectives State four environmental roles of protists. Describe algal blooms and red tides and their impact. State an important role for protists in research. List a use of protists as food and three uses of protist byproducts. Describe four protist-caused diseases.

39. Section 4 Protists and Humans Chapter 25 Protists in the Environment Protists produce large amounts of oxygen, form the foundation of food webs, recycle materials, and play a role in several symbiotic relationships.

40. Section 4 Protists and Humans Chapter 25 Protists in the Environment, continued Ecology of Protists –Algal blooms can lead to the depletion of oxygen in water. –Red tides produce harmful toxins.

41. 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.

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

43. Section 4 Protists and Humans Chapter 25 Protists in Industry, continued Protist Byproducts –Protists provide important byproducts, such as alginate, carrageenan, and agar.

44. Section 4 Protists and Humans Chapter 25 Protists and Health Parasitic protists cause malaria, giardiasis, cryptosporidiosis, and trichomoniasis in humans.

45. 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.

46. Chapter 25 Life Cycle of Plasmodium Section 4 Protists and Humans

47. Chapter 25 Click below to watch the Visual Concept. Visual Concept Malaria Life Cycle Section 4 Protists and Humans