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The Kingdom Protista. Chapter 20. What is a Protist?. Any organism that is not a plant, an animal, a fungus, or prokaryote. Are eukaryotes that are not members of the kingdoms, Plantae, Animalia, or Fungi. Classification of Protists.
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The Kingdom Protista Chapter 20
What is a Protist? • Any organism that is not a plant, an animal, a fungus, or prokaryote. • Are eukaryotes that are not members of the kingdoms, Plantae, Animalia, or Fungi
Classification of Protists • Protists are so diverse that many biologists suggest that they should be broken up into several kingdoms. • Unfortunately, biologist do not agree on how to classify the protists.
Animallike Plantlike Funguslike Take in food from the environment Produce food by photosynthesis Obtain food by external digestion Decomposers Parasites Classification of Protists Section 20-1 Protists are classified by which include which which which
Animallike Protists: Protozoans • 4 phyla of the animallike protists -Distinguished from one another by their means of movement • Zooflagellates-move by flagella ex. Trychonympha(termite), Trypanosoma(Tse Tse Fly) • Sarcodines-move by pseudopods ex. amoeba • Ciliates-move by cilia ex. paramecium • Sporozoans-no movement, parasites ex. plasmodium
Zooflagellates • Animallike protists that swim using a flagella • Most have 1-2 flagella • Live in lakes & streams, where they absorb nutrients from decaying matter • Some live within bodies of other organisms, taking advantage of the food from larger organisms • Can reproduce by asexual and sexual reproduction
Sarcodines • Move via temporary cytoplasmic projections known as pseudopods • Amoebas • Surround food and form a food vacuole
Contractile vacuole Pseudopods Nucleus Food vacuole Amoeba
Ciliates • Contain short hairlike projections called cilia • Use cilia for feeding & movement • Found in both fresh & salt water
Trichocysts Oral groove Lysosomes Gullet Anal pore Contractile vacuole Micronucleus Macronucleus Food vacuoles Cilia Ciliates
Sporozoans • Do not move on their own & are parasitic
Animallike Protists & Disease • Malaria • African sleeping sickness • Amebic dysentery
Malaria • One of the world’s most serious infectious disease • 2 million people still die from malaria every year • Carried by the female Anopheles mosquito
Symptoms & Treatment of Malaria • Severe chills • Fever • There are a number of vaccines against malaria but to date most are only partially effective • Controlling mosquitoes is the best method to controlling malaria
African Sleeping Sickness • Zooflagellates of the genus Trypanosoma • Spread by the bite of an insect known as the tsetse fly
Symptoms • Begin to show 1 to 4 weeks after bite • Chills • Rashes • Infect nerve cells: severe damage causes some individuals to lose consciousness, lapsing into a deep and sometimes fatal sleep
Treatment • Hospitalization • Medications • Follow-ups for 2 years
Amebic Dysentery • Common in areas with poor sanitation • Severe diarrhea • Caused by an organism that looks like the harmless amoebas • Entamoeba, a parasite spread by contaminated drinking water • Attacks the wall of the intestine, causing extensive bleeding
Amebic Dysentery • Can also occur in the crystal-clear mountain streams • Caused by another flagellated pathogen, Giardia • Giardia produces tough, microscopic-size cysts that can be killed only be boiling water thoroughly or by adding iodine to the water • Causes severe diarrhea and digestive system problems.
Ecology of Animallike Protists • Essential roles in the living world • Live symbiotically with other organisms • Recycle nutrients by breaking down dead organic matter • Live in seas and lakes & are a part of the food chain
Trichonympha • Zooflagellate that lives within the digestive systems of termites • Makes it possible for termites to eat wood • Termites do not have an enzyme to breakdown wood • The Trichonympha does it for them
Homework • Guided Reading Worksheets • 20-1 • 20-2 • Due Wednesday, February 16th
Plant-Like Protists • Commonly called Algae • Contain chlorophyll and carries out photosynthesis
Unicellular Algae-classified by pigments • Phylum Euglenophyta • 2 flagella but no cell wall • Phylum Chrysophyta • Gold-colored chloroplast • Phylum Bacillariophyta • Called diatoms • Cell walls contain silicon • Phylum Pyrrophyta • Called dinoflagellates
Draw a Euglena • see p. 507, Figure 20-10)
Ecology of Unicellular Algae • Make up most of phytoplankton • Small photosynthetic organisms near surface of ocean • ½ of all photosynthesis on Earth is performed by the algae • Source of nourishment for small fish
Algal Blooms and “Red Tides • Help recycle sewage and fertilizer • Grow too much, deplete nutrients, die, rid water of oxygen, choke out fish life • Can produce toxins, eaten by clams and shellfish, eaten by humans and cause death
Multicellular Algae (mostly) • Phylum Rhodophyta • Red Algae • Phylum Phaeophyta • Brown Algae • Phylum Chlorophyta • Green Algae
Draw Brown Algae • see p. 511, Figure 20-15
Reproduction • Alternation of Generations • Life cycle includes both haploid and diploid generation • Enables them to survive unfavorable conditions
Analyzing Data • Pg. 508 • Questions 1-4
Fungus-Like Protists • Like fungi-absorb nutrients from dead or decaying organic matter • Different from fungi-have centrioles and lack chitin cell walls
Funguslike Phyla • Phylum Acrasiomycota • Slime mold • Phylum Myxomycota • Acellular slime mold • Phylum Oomycota • Water mold (white mold on dead fish)
The Great Potato Famine • Phytophthora infestans (Phylum Oomycete) destroyed 60% of the potatoes in Ireland in 1845 • Between 1845 and 1851 at least one million Irish people died of starvation or disease • One million Irish emigrated to the U.S. and other countries
Homework • Guided Reading Worksheets • 20-3 • 20-4 • 20-5 • Preparing for TAKS pg. 525 1-4 • Due Friday, February 18th