The Kingdom Protista

1. The Kingdom Protista

2. What Is a Protist?

3. Classification of Protists • One way protists can be classified is by how they obtain nutrition: • Heterotrophs are called animal-like protists. • Photosynthesizers are called plantlike protists. • Decomposers and parasites are called funguslike protists.

4. Animal-like Protists: Protozoans

5. 20-2 Animal-like Protists: • There are four phyla of animal-like protists: • zooflagellates • sarcodines • ciliates • sporozoans • Animal-like protists are classified by their means of movement.

6. Zooflagellates • Zooflagellates • What are the distinguishing features of the zooflagellates?

7. Sarcodines • Sarcodines • What are the distinguishing features of the sarcodines?

8. Sarcodines • Amoebas • Amoebas are flexible, active cells with thick pseudopods that extend out of the central mass of the cell. • Cytoplasm streams into the pseudopod, and the rest of the cell follows. • This type of locomotion is known as amoeboid movement.

9. Structures of an Amoeba Contractile vacuole Pseudopods Nucleus Food vacuole

10. Sarcodines • Amoebas reproduce by mitosis and cytokinesis.

11. Ciliates • Ciliates • What are the distinguishing features of the ciliates?

12. Ciliates • Structures of a Paramecium

13. Ciliates • Paramecia possess two types of nuclei: • The macronucleus keeps multiple copies of most genes that the cell needs in its day-to-day existence. • The micronucleus contains a copy of all of the cell's genes.

14. Sporozoans • Sporozoans • What are the distinguishing features of the sporozoans?

15. Sporozoans • Many sporozoans have complex life cycles that involve more than one host. • Sporozoans reproduce by sporozoites. • A sporozoite can attach itself to a host cell, penetrate it, and then live within it as a parasite.

16. Animal-like Protists and Disease • Animal-like Protists and Disease • How do animal-like protists harm other living things?

17. Animal-like Protists and Disease • Malarial Infection

18. Animal-like Protists and Disease • A female Anopheles mosquito bites a human infected with malaria and picks up Plasmodium gamete cells.

19. Animal-like Protists and Disease • The sexual phase of the Plasmodium life cycle takes place inside the mosquito.

20. Animal-like Protists and Disease • Gametes fuse to form zygotes, meioses occurs, and sporozoites are produced and migrate to salivary gland.

21. Animal-like Protists and Disease • Infected mosquito bites another human, injecting saliva that contains Plasmodium sporozoites. Plasmodium sporozoites

22. Animal-like Protists and Disease • Sporozoites infect liver cells and multiply asexually. Plasmodium sporozoites Liver

23. Animal-like Protists and Disease • Infected liver cells burst, releasing Plasmodium cells called merozoites that infect red blood cells. Plasmodium sporozoites Liver Merozoites Liver cells burst

24. Animal-like Protists and Disease • Merozoites reproduce asexually inside red blood cells. Merozoites Red blood cells

25. Animal-like Protists and Disease • Infected red blood cells burst, releasing merozoites that infect other red blood cells. Some cells release gametes that can infect mosquitoes. Merozoites Red blood cells

26. Plantlike Protists: Unicellular Algae

27. Plantlike Protists • Plantlike protists contain chlorophyll and carry out photosynthesis. • Plantlike protists are commonly called “algae.” • Algae are sometimes classified with the plants.

28. Plantlike Protists • The four phyla of unicellular algae are: • euglenophytes • chrysophytes • diatoms • dinoflagellates

29. Euglenophytes • Euglenophytes • What are the distinguishing features of the euglenophytes?

30. Euglenophytes Pellicle Contractile vacuole Carbohydrate storage bodies Chloroplast Nucleus Eyespot Gullet Flagella

31. Euglenophytes • Near the gullet is a reddish pigment known as the eyespot, which helps find sunlight to power photosynthesis. • Euglenas can also live as heterotrophs. Eyespot

32. Euglenophytes Pellicle • Euglenas do not have cell walls. Instead, they have an intricate cell membrane called a pellicle. • The pellicle folds into ridges, each supported by microtubules.

33. Euglenophytes • Euglenas reproduce asexually by binary fission.

34. Chrysophytes • Chrysophytes • What are the distinguishing features of the chrysophytes?

35. Chrysophytes • The cell walls of some chrysophytes contain the carbohydrate pectin rather than cellulose, and others contain both. • Chrysophytes store food in the form of oil rather than starch. • They reproduce both asexually and sexually. • Most are solitary, but some form threadlike colonies.

36. Diatoms • Diatoms • What are the distinguishing features of the diatoms?

37. Dinoflagellates • Dinoflagellates • What are the distinguishing features of the dinoflagellates?

38. Dinoflagellates • Dinoflagellates have two flagella that fit in grooves between two thick plates of cellulose that protect the cell. • Most dinoflagellates reproduce asexually by binary fission. • Many dinoflagellates are luminescent. When they are agitated, they give off light.

39. Plantlike Protists: Red, Brown, and Green Algae

40. Plantlike Protists: Red, Brown, and Green Algae • The three phyla of algae that are largely multicellular are: • red algae • brown algae • green algae

41. Red Algae • Red Algae • What are the distinguishing features of red algae?

42. Brown Algae • Brown Algae • What are the distinguishing features of brown algae?

43. Brown Algae • Brown Alga Structure Blades Bladder Stipe Holdfast

44. Green Algae • Green Algae • What are the distinguishing features of green algae?

45. Funguslike Protists

46. What are the similarities and differences between funguslike protists and fungi?

47. Slime Molds • Slime Molds • What are the defining characteristics of the slime molds?

48. Slime Molds • Two groups of slime molds are recognized: • Cellular slime molds, whose individual cells remain separated during every phase of the mold's life cycle. • Acellular slime molds, which pass through a stage in which its cells fuse to form large cells with many nuclei.

49. Slime Molds • Cellular Slime Molds  • Most cellular slime molds live as free-living cells that are not easily distinguishable from soil amoebas. • In nutrient-rich soils, these amoeboid cells reproduce sexually and produce diploid zygotes.

50. Slime Molds Fruiting body • Life Cycle of a Cellular Slime Mold Solitary cell Emerging amoebas Spores Aggregated amoebas Zygote Fruiting body Migrating colony