1. End Show Slide 1 of 33 Copyright Pearson Prentice Hall biology

2. End Show Slide 2 of 33 Copyright Pearson Prentice Hall 20-3 Plantlike Protists: Unicellular Algae

3. End Show 20-3 Plantlike Protists: Unicellular Algae Slide 3 of 33 Copyright Pearson Prentice Hall Plantlike protists contain chlorophyll and carry out photosynthesis. Plantlike protists are commonly called “algae.” Algae are sometimes classified with the plants. Plantlike Protists

4. End Show 20-3 Plantlike Protists: Unicellular Algae Slide 4 of 33 Copyright Pearson Prentice Hall The four phyla of unicellular algae are: euglenophytes chrysophytes diatoms dinoflagellates Plantlike Protists

5. End Show 20-3 Plantlike Protists: Unicellular Algae Slide 5 of 33 Copyright Pearson Prentice Hall Chlorophyll and Accessory Pigments What is the function of chlorophyll and accessory pigments in algae? Chlorophyll and Accessory Pigments

6. End Show 20-3 Plantlike Protists: Unicellular Algae Slide 6 of 33 Copyright Pearson Prentice Hall Chlorophyll and Accessory Pigments Chlorophyll and accessory pigments allow algae to harvest and use the energy from sunlight.

7. End Show 20-3 Plantlike Protists: Unicellular Algae Slide 7 of 33 Copyright Pearson Prentice Hall Chlorophyll and Accessory Pigments One trait used to classify algae is the type of photosynthetic pigments they contain.

8. End Show 20-3 Plantlike Protists: Unicellular Algae Slide 8 of 33 Copyright Pearson Prentice Hall Some algae have evolved different forms of chlorophyll—a, b, and c—that absorb different wavelengths of light. Accessory pigments absorb light at different wavelengths than chlorophyll, giving algae a variety of colors. Chlorophyll and Accessory Pigments

9. End Show 20-3 Plantlike Protists: Unicellular Algae Slide 9 of 33 Copyright Pearson Prentice Hall Euglenophytes What are the distinguishing features of the euglenophytes?

10. End Show 20-3 Plantlike Protists: Unicellular Algae Slide 10 of 33 Copyright Pearson Prentice Hall Euglenophytes Euglenophytes are plantlike protists that have two flagella but no cell wall.

11. End Show 20-3 Plantlike Protists: Unicellular Algae Slide 11 of 33 Copyright Pearson Prentice Hall Euglena Euglenophytes Gullet Flagella Eyespot Pellicle Contractile vacuole Carbohydrate storage bodies Chloroplast Nucleus

12. End Show 20-3 Plantlike Protists: Unicellular Algae Slide 12 of 33 Copyright Pearson Prentice Hall Two flagella emerge from a gullet in the cell. The longer of the flagella spins so it pulls the organism rapidly through the water. Euglenophytes Gullet Flagella

13. End Show 20-3 Plantlike Protists: Unicellular Algae Slide 13 of 33 Copyright Pearson Prentice Hall Near the gullet is a reddish pigment known as the eyespot, which helps find sunlight to power photosynthesis. Euglenas can also live as heterotrophs. Euglenophytes Eyespot

14. End Show 20-3 Plantlike Protists: Unicellular Algae Slide 14 of 33 Copyright Pearson Prentice Hall Euglenas store carbohydrates in small storage bodies. Euglenophytes Carbohydrate storage bodies

15. End Show 20-3 Plantlike Protists: Unicellular Algae Slide 15 of 33 Copyright Pearson Prentice Hall 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. Euglenophytes Pellicle

16. End Show 20-3 Plantlike Protists: Unicellular Algae Slide 16 of 33 Copyright Pearson Prentice Hall Euglenophytes Euglenas reproduce asexually by binary fission.

17. End Show 20-3 Plantlike Protists: Unicellular Algae Slide 17 of 33 Copyright Pearson Prentice Hall Chrysophytes What are the distinguishing features of the chrysophytes?

18. End Show 20-3 Plantlike Protists: Unicellular Algae Slide 18 of 33 Copyright Pearson Prentice Hall Chrysophytes Members of the phylum Chrysophyta are a diverse group of plantlike protists that have gold-colored chloroplasts.

19. End Show 20-3 Plantlike Protists: Unicellular Algae Slide 19 of 33 Copyright Pearson Prentice Hall 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.

20. End Show 20-3 Plantlike Protists: Unicellular Algae Slide 20 of 33 Copyright Pearson Prentice Hall Diatoms What are the distinguishing features of the diatoms?

21. End Show 20-3 Plantlike Protists: Unicellular Algae Slide 21 of 33 Copyright Pearson Prentice Hall Diatoms Diatoms produce thin, delicate cell walls rich in silicon (Si)—the main component of glass. The walls are shaped like the two sides of a petri dish or flat pillbox, with one side fitted snugly into the other.

22. End Show 20-3 Plantlike Protists: Unicellular Algae Slide 22 of 33 Copyright Pearson Prentice Hall Dinoflagellates What are the distinguishing features of the dinoflagellates?

23. End Show 20-3 Plantlike Protists: Unicellular Algae Slide 23 of 33 Copyright Pearson Prentice Hall Dinoflagellates About half of the dinoflagellates are photosynthetic; the other half live as heterotrophs.

24. End Show 20-3 Plantlike Protists: Unicellular Algae Slide 24 of 33 Copyright Pearson Prentice Hall 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.

25. End Show 20-3 Plantlike Protists: Unicellular Algae Slide 25 of 33 Copyright Pearson Prentice Hall Ecology of Unicellular Algae Plantlike protists are important to freshwater and marine ecosystems because they make up the base of the food chain in many aquatic ecosystems.

26. End Show 20-3 Plantlike Protists: Unicellular Algae Slide 26 of 33 Copyright Pearson Prentice Hall Ecology of Unicellular Algae Phytoplankton constitute the population of small, photosynthetic organisms found near the surface of the ocean. Phytoplankton carry out half of Earth’s photosynthesis. In addition, they provide nourishment for many organisms.

27. End Show 20-3 Plantlike Protists: Unicellular Algae Slide 27 of 33 Copyright Pearson Prentice Hall Ecology of Unicellular Algae Algal Blooms Many protists are vital in recycling sewage and other wastes. When waste is excessive, algae may grow into enormous masses known as blooms, which deplete water of nutrients. Their decomposition robs water of oxygen, killing fish and invertebrate life.

28. End Show - or - Continue to: Click to Launch: Slide 28 of 33 Copyright Pearson Prentice Hall 20-3

29. End Show Slide 29 of 33 Copyright Pearson Prentice Hall 20-3 The function of accessory pigments in various groups of algae is to a.absorb red and violet light. b.carry out photosynthesis in the absence of chlorophyll. c.increase the range of wavelengths used for photosynthesis. d.carry out photosynthesis when sunlight is not available.

30. End Show Slide 30 of 33 Copyright Pearson Prentice Hall 20-3 Which of the following describes structures found in euglenophytes? a.chloroplasts but no cell walls b.chloroplasts and cell walls c.cell walls but no chloroplasts d.no cell walls or chloroplasts

31. End Show Slide 31 of 33 Copyright Pearson Prentice Hall 20-3 Plantlike protists with gold-colored chloroplasts are the a.euglenophytes. b.diatoms. c.chrysophytes. d.dinoflagellates.

32. End Show Slide 32 of 33 Copyright Pearson Prentice Hall 20-3 The base of most marine food chains is made up of a.zooplankton. b.euglenophytes. c.phytoplankton. d.chrysophytes.

33. End Show Slide 33 of 33 Copyright Pearson Prentice Hall 20-3 The effect of algal “blooms” on other organisms is that they a.poison consumers that eat filter-feeders such as clams. b.serve as an important food source for fish and crustaceans. c.decompose dead and decaying organisms. d.convert inorganic molecules into energy-rich food molecules.

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