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PROTISTS
Chapter 19 - 1
3 groups of Protists:
Animal-like ProtistsAnimal-like Protists
Plant-like ProtistsPlant-like Protists
Fungus-like ProtistsFungus-like Protists
PROTISTS
All are All are eukaryoteseukaryotes – – have a nucleus and have a nucleus and membrane-bound membrane-bound organelles.organelles.
4
Endosymbiotic Endosymbiotic TheoryTheory
-How Eukaryotes came to be--How Eukaryotes came to be-Scientists think protists were the first Scientists think protists were the first eukaryotes to evolve.eukaryotes to evolve.Endosymbiosis refers to one species living Endosymbiosis refers to one species living within another (the host)within another (the host)
Movement of smaller photosynthetic & Movement of smaller photosynthetic & heterotrophic prokaryotes into larger prokaryotic heterotrophic prokaryotes into larger prokaryotic host cellshost cells
Formed cell organellesFormed cell organelles chloroplast
mitochondria
Animal-Like Protists“Protozoans”
19 - 2
PROTOZOANS
UnicellularUnicellular – made up of – made up of one one
cell.cell.
HeterotrophsHeterotrophs – they eat – they eat other organisms or dead other organisms or dead organic matter.organic matter.
ClassifiedClassified by how they by how they movemove
4 PHYLA OF PROTOZOANS
Ciliophora (Ciliates)
Sarcodina (Amoeba)
Apicomplexa (Sporozoa)
Zoomastigina (Flagellates)
PHYLUM CILIOPHORA
Ciliates – Use Cilia for movement.
found in fresh and salt waterDraw and label p.548
Phylum Cilophora
paramecium
Phylum Cilophora
Phylum Ciliophora
TWO KINDS OF NUCLEI:Macronucleus – controls daily functions such as feeding, eliminating waste, and maintaining water balance
Micronucleus – used for reproduction
Phylum Ciliophora
Reproduce Asexually, but maintain genetic variation through Conjugation: exchange genetic info
PHYLUM SARCODINA
Pseudopods- (“fake feet”) used for feeding and locomotion.Saltwater and freshwaterAsexual reproduction
Draw the example - amoeba
pseudopods
nucleus
Food vacuole
Sarcodina 3D
Sarcodina
Foraminifera - have a protective shell or TEST, usually made of calcium carbonate
layers of tests can deposit on the ocean floor
these can form limestone and chalk, like the White Cliffs of Dover
Some species of forams are good indicators of oil deposits below
Cliffs of Dover
PHYLUM APICOMPLEXA
Sporozoans- Form spores at some point in their life cycle.Lack locomotionSexual and Asexual reproductionIntestinal parasites
Plasmodium (Malaria)
It’s Vector: Anopheles Mosquito
Phylum Apicomplexa
Malaria in red blood cells
PHYLUM ZOOMASTIGINA
Flagellates- move using flagella
Free living by absorbing dead or decaying organic matter OR some are parasites
EX:Trichonympha lives in the gut of termites (helps termite digest wood)
Trichomonas Trichomonas vaginalis: vaginalis: an STDan STD
Zoomastigina
Tsetse Fly: carries Trypanosoma to humans; in other words, it’s a Vector for African Sleeping Sickness
American Sleeping Sickness (Chagas disease) – carried by reduviid bug
Phylum Zoomastigina
Plant-Like Protists“Algae”
19 - 3
PROTISTS
PLANT-LIKE PROTISTSMost perform photosynthesisContain chlorophyll (green pigment) and possibly secondary pigmentsClassified by their pigment color
ALGAE
Phyla of AlgaeDiatoms - BacillariophytaDinoflagellates - PyrrophytaEuglenoids - EuglenophytaYellow/Green algae - ChrysophytaBrown algae - PhaeophytaGreen algae - ChlorophytaRed algae - Rhodophyta
DIATOMS
Phyla of AlgaeDiatoms- “The Golden Boxes”Made of chlorophyll (green) & carotenoids (golden-yellow)Reproduction- sexual and asexual.Cell wall- made of hard silica (glass)
Diatoms
Made of 2 halves: The smaller half fits inside the bigger half, like a box and lid.Store their food as oil, so they float at the top of the water where they can get sunlight for photosynthesis.
Dinoflagellate
DINOFLAGELLATES
Phyla of AlgaeDinoflagellates- “The spinning ones”2 flagella at right angles to eachother, causes it to spin as it moves.Mostly found in saltwater.Can be bioluminescent: Glow
Dinoflagellates
ALGAL BLOOMS:In good conditions, will reproduce in GREAT numbers.Clog fish gillsDie, decompose, and deplete the oxygen supply, suffocating marine life.
Dinoflagellates
The RED TIDEDinoflagellates with red secondary pigments.Produce a lethal nerve toxinDON’T EAT THE SHELLFISH… you will die.Shellfish filter water, eating the dinoflagellates.
PROTISTS
RED TIDE
EUGLENOIDS
Phyla of AlgaeEuglenoids- “The survivors” have both plant and animal characteristics.Use photosynthesis or absorb nutrients from the environment like a heterotroph.
Euglenoids
Have an “eye spot” that is sensitive to light.
CHRYSOPHYTES
Phyla of AlgaeChrysophytes- “The Colonists”Yellow-Brown secondary pigments (carotenoids)Form colonies- a group of cells that live in close association.
Brown Algae
Phyla of AlgaeBrown algae- “The Brown Ones”Fucoxanthin pigmentsMulticellularLargest algae
Ex: Giant Kelp can grow up to 30-60 cm a day.
Brown Algae
Used to make a variety of productsAs a thickening agent in puddings, ice creamUsed as food for animals (processed)
Brown Algae
GREEN ALGAE
Phyla of AlgaeGreen algae- “The Green Ones”Mostly freshwaterVery similar to plant cell wallsChloroplasts w/ chlorophyll pigments
Green Algae
Scientists think the first plants may have evolved from green algae.
RED ALGAE
Phyla of AlgaeRed algae- “The Red Ones”Warm saltwater habitatsPerform photosynthesis
Even at depths of 100 meters!
Red & blue secondary pigments (phycobilins).
Red Algae
Seaweed
Red Algae
Example: Red moss
Fungus-Like Protists
19 - 4
FUNGUS-LIKE PROTISTS
FUNGUS-LIKE PROTISTS
(MOLDS and MILDEWS)
Most are small and live in damp/dark places.Protists that act as decomposers are called molds.Classified by body form.
Fungus-like protists
3 types:Acellular slime moldsCellular slime moldsWater molds and Downy mildews
SLIME MOLDS
Use spores to reproduce.Feed on decaying matter.Absorb nutrients through cell wall.
SLIME MOLDS
ACELLULAR SLIME MOLDSPhylum Myxomycota
“Not Cellular”Can grow as much as 50 grams and 30cm and be as large as a human hand (one cell!)Single cell with many nuclei
Myxomycota - plasmodium
Myxomycota
http://biodidac.bio.uottawa.ca/ftp/BIODIDAC/Protista/Myxomyco/diagbw/Myxo005b.gif
Myxomycota Life Cycle
SLIME MOLDS
CELLULAR SLIME MOLDSPhylum Acrasiomycota
Single cellsCan congregate to form one slug-like organism.Ex. Dictyostelium
Phylum Acrasiomycotaaggregating
amoebas
colony & fruiting body
http://sps.k12.ar.us/massengale/algal__fungal_protist_notes_b1.htm
Acrasiomycota Life Cycle
Oomycota
WATER MOLDS and DOWNY MILDEW
DecomposersSurround food source with a mass of threads, break down tissues, and absorb nutrients.Downy mildew: Irish Potato famine.
http://agronomia.uchile.cl/webcursos/microbiologiagral/pagina%20microbiologia1/micologia/fotos/oomycota.gif
Examples:
water molds
downy mildews
white rusts
Oomycota Life Cycle
http://protist.i.hosei.ac.jp/PDB/Galleries/Klos/Bavaria/Leptomitus_1.html
http://www.anselm.edu/homepage/jpitocch/genbios/28-x2-PowderyMildew.jpg
Phylum Oomycota
potatoes are native to North America they were introduced to Europe and became a staple of the dietduring the summer of 1846 most of the potato crop was destroyed by Phytophthora (an oomycota)nearly 1,000,000 Irish people died, and 1,500,000 emigrated to other countries, like the U.S.
PROTISTS
IMPORTANCE OF PROTISTSECOLOGICAL ROLES
Provide an essential food base in aquatic food chainsCarry out more than 30-40% of Earth’s photosynthesisProtozoans help keep the number of bacteria in check