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CHAPTER 20 PROTISTS

CHAPTER 20 PROTISTS. Question of the DAY Apr 21 EOC REVIEW. The oldest fossils that have been found are of single-celled organisms. This suggests that life on Earth A. has become less complex as the atmosphere has changed B. changes in response to mutations but not environment

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CHAPTER 20 PROTISTS

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  1. CHAPTER 20PROTISTS

  2. Question of the DAY Apr 21EOC REVIEW • The oldest fossils that have been found are of single-celled organisms. This suggests that life on Earth • A. has become less complex as the atmosphere has changed • B. changes in response to mutations but not environment • C. mutates in order to adapt to new environments • D. has evolved over time from simple to complex organisms

  3. DO NOW Apr 21EOC REVIEW • Draw and label a graph to illustrate a change in finch population if the environment changes to favor large beaks.

  4. DO NOW ANSWERED Apr 21 • Recall that this type of change is known as Directional Selection.

  5. AGENDA APRIL 21 • OBJECTIVES: Explain the characteristics used to classify protists. • 1. EOC REVIEW QUESTIONS • 2. Begin Chapter 20 Protists • 3. Review and HOMEWORK • Guided Reading Packet • DUE WEDNESDAY Apr 23 • CONTINUE TO REVIEW YOUR NOTES EVERY DAY!!! • Combined Chapter Test – DATE TBA

  6. 20-1: Kingdom Protista • Protists are eukaryotes. • WHAT FEATURES ARE FOUND IN EUKARYOTES? • Nucleus and membrane bound organelles • Members DO NOT belong to Kingdoms Plantae, Animalia, or Fungi • Most are unicellular. • A few consist of hundreds or thousands of cells. • Macrocysticpyrifera

  7. Protists • First eukaryotic organisms on Earth were protists • 1.5 billion years ago • Very diverse group of organisms • Classified by the way they obtain nutrition. • Animallikeprotists = Heterotrophs • Plantlike protists = Photosynthetic protists • Funguslikeprotists = Decomposers

  8. 20-2: AnimallikeProtists - Protozoans • Zooflagellates • Swim using flagella • Absorb food through cell membrane • Reproduce asexually by mitosis and cytokinesis • Genetically identical cells • Some perform meiosis • New combination of genetic material

  9. 20-2: Zooflagellates • Sarcodinesmove and feed using pseudopods. • Amoeboid movement • Engulf food and other cells • Stored in food vacuoles until digested • Reproduce by mitosis and cytokinesis

  10. 20-2: Zooflagellates • Ciliates use cilia for feeding and movement. • Cilia have same internal structure as flagella • Parameceum • Cilia arranged in evenly spaced rows and bundles • Trichocysts protect the cell from danger • Release spike-like projections

  11. CILIATES • Internal Anatomy • Macronucleus – Holds working genes for existence • Micronucleus – Contains a reserve copy of genes • Cilia sweep food into gullet • Lysosomes digest food • Maintain homeostasis using contractile vacuoles • Collect and release water • Can perform Conjugation • Exchange of micronuclei with other cells

  12. QUESTION of the DAY APR 22 • Viruses are exceptions to the cell theory, but they have some characteristics of living things. What is one of these characteristics? • A. They are made up of many specialized cells. • B. They contain genetic material. • C. They reproduce by mitosis. • D. They contain chlorophyll.

  13. Which statement best explains the patterns seen in these diagrams? • A. The organisms at the end of each branch can be found in the environment today. • B. The organisms that are living today have all evolved at the same rate and have undergone the same kinds of changes. • C. Evolution involves changes that give rise to a variety of organisms, some of which continue to change through time while others die out. • D. These patterns cannot be used to illustrate the evolution of extinct organisms.

  14. AGENDA APRIL 22 • OBJECTIVES: Explain the characteristics used to classify protists. • 1. EOC REVIEW QUESTIONS • 2. Chapter 20-2 and 20-3 Protists • 3. Review and HOMEWORK • WORK ON GUIDED READING PACKET • CONTINUE TO REVIEW YOUR NOTES EVERY DAY!!! • Combined Chapter Test – DATE TBA

  15. 20-2 AnimallikeProtists and Disease • Sporozoansdo not move on their own • Parasites • MALARIA caused by sporozoanPlasmodium • Carried by female Anopheles mosquito • African Sleeping Sickness caused by trypanosomes. • Bite of a tsetse fly • Destroy red blood cells, nerve cells, and can lead to a fatal sleep

  16. 20-3: Plantlike Protists • 20-2 Trichonymphaproduce cellulase. • Live in guts of termites • Digest wood • 20-3 UNICELLULAR ALGAE perform photosynthesis. • Contain chlorophyll a, b, and c and accessory pigments • Euglenophytes have two flagella but no cell wall • Reddish pigment called eyespot helps them find sunlight

  17. 20-3: Plantlike Protists • Chrysophytes have gold-colored pigments • Cell walls contain the carbohydrate PECTIN • Diatoms produce thin cell walls rich in silicon (Si). • Dinoflagellates are often luminescent. • Photosynthetic Phytoplankton provide food • ALGAL BLOOMS deplete nutrients and oxygen

  18. 20-4: Red, Brown, Green Algae • RED Algaelive deep in the oceans • Contain Phycobilins that absorb blue light • BROWN Algae are multicellular • Largest and most complex • GREEN Algae are very similar to land plants • Cell walls contain cellulose • Contain Chlorophyll a and b • Store food as Starch

  19. ALTERNATION of GENERATIONSREFER to FIGURE 20-17 PAGE 513 Normal Living Conditions Unfavorable Living Conditions Haploid cells undergo mitosis but release gametes Two mating types PLUS + and MINUS – + and – gametes fuse together Form a diploid zygote By MEIOSIS, zygote produces 4 haploid cells • Haploid cells reproduce asexually • Mitosis produces zoospores • Zoospores genetically identical to the haploid cell that entered Mitosis

  20. Uses of ALGAE • Source of Food • Chemicals produced used in medicines and treatments • Industrial uses in plastics, paints, and electronics • Research uses in AGAR plates

  21. 20-5 FunguslikeProtists • Slime Molds recycle organic materials • Reproduce asexually and sexually • Cellular slime molds remain distinct and separated • Acellular slime molds fuse together into plasmodia • large cells with many nuclei • Water Molds feed on dead/decaying matter

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