chapter 20 protists
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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 - PowerPoint PPT PresentationTRANSCRIPT
CHAPTER 20PROTISTS
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
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.
DO NOW ANSWERED Apr 21 Recall that this type of change is known as Directional Selection.
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 PacketDUE WEDNESDAY Apr 23
CONTINUE TO REVIEW YOUR NOTES EVERY DAY!!!Combined Chapter Test – DATE TBA
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.
Macrocystic pyrifera
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.Animallike protists = HeterotrophsPlantlike protists = Photosynthetic protists Funguslike protists = Decomposers
20-2: Animallike Protists - Protozoans
Zooflagellates
Swim using flagella
Absorb food through cell membrane
Reproduce asexually by mitosis and cytokinesisGenetically identical cells
Some perform meiosisNew combination of genetic material
20-2: Zooflagellates Sarcodines move and feed using pseudopods.
Amoeboid movement
Engulf food and other cellsStored in food vacuoles until digested
Reproduce by mitosis and cytokinesis
20-2: Zooflagellates Ciliates use cilia for feeding and movement.
Cilia have same internal structure as flagella
ParameceumCilia arranged in evenly spaced rows and bundles
Trichocysts protect the cell from dangerRelease spike-like projections
CILIATES Internal Anatomy
Macronucleus – Holds working genes for existenceMicronucleus – Contains a reserve copy of genes
Cilia sweep food into gulletLysosomes digest food
Maintain homeostasis using contractile vacuolesCollect and release water
Can perform Conjugation Exchange of micronuclei with other cells
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.
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.
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
20-2 Animallike Protists and Disease Sporozoans do not move on their own
Parasites
MALARIA caused by sporozoan Plasmodium 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
20-3: Plantlike Protists 20-2 Trichonympha produce cellulase.
Live in guts of termitesDigest wood
20-3 UNICELLULAR ALGAE perform photosynthesis.Contain chlorophyll a, b, and c and accessory pigments
Euglenophytes have two flagella but no cell wallReddish pigment called eyespot helps them find sunlight
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
20-4: Red, Brown, Green Algae RED Algae live 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
ALTERNATION of GENERATIONSREFER to FIGURE 20-17 PAGE 513Normal Living
Conditions Haploid cells reproduce
asexually
Mitosis produces zoospores
Zoospores genetically identical to the haploid cell that entered Mitosis
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
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
20-5 Funguslike Protists Slime Molds recycle organic materials
Reproduce asexually and sexuallyCellular slime molds remain distinct and separatedAcellular slime molds fuse together into plasmodia
large cells with many nuclei
Water Molds feed on dead/decaying matter