Kingdom Protista

Kingdom Protista
*members of this kingdom are grouped together because they do not fit into other kingdoms
Plant-like Protists
(Algae)
Animal-like Protists
(Protozoa)
photosynthetic autotrophs*
Unicellular
• Euglenophyta - ex. euglena*
• Chrysophyta - ex. diatoms
• Pyrrophyta - ex. dinoflagellates
Multicellular
• Chlorophyta - ex. ulva (sea lettuce)
• Phaeophyta - ex. kelp
• Rhodophyta - ex. Irish moss
Title: Apr 28­9:14 PM (1 of 16)
heterotrophs
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Fungus-like Protists
heterotrophs
• Myxomycota - slime molds
Sarcodina - ex. amoeba
• Oomycota - water molds
Ciliophora - ex. paramecium
Zoomastigophora - ex. trypanosome
Sporozoa - ex. plasmodium
Plant-like Protists (Algae)
Unicellular
Title: Apr 29­9:33 PM (2 of 16)
Phylum Euglenophyta
Representative: Euglena
General Features:
• rounded anterior, pointed posterior
• hard outside covering called pellicle
• cytoplasm: clear ectoplasm, dense endoplasm
• live in fresh water
• contractile vacuole to remove excess water
Food Getting:
• have chloroplasts for photosynthesis
• also absorb nutrients by diffusion
Title: Apr 29­6:26 AM (3 of 16)
Movement:
• flagellum in front to draw through water
• euglenoid mvmt: shorten and extend body
Reproduction:
• asexually by binary fission
• form dormant cyst in unfavorable conditions
Response to Stimuli:
• light: eyespot detects light, move twds it
• water: if pond dries up, forms cyst
pond sample
euglenoid movement
binary fission
http://www.btinternet.com/~stephen.durr/euglena.html
Title: Apr 29­6:44 AM (4 of 16)
cysts
Phylum Chrysophyta
Representative: Diatoms
General Features:
• fresh water and salt water
• most imp/abundant primary producers in aquatic env
• body structure: two halves called valves
• valves fit like top and bottom of shoe box
• valves are made of silica (sand, glass component)
• mined and used as abrasive in polishes, toothpaste...
Food Getting:
• have chromoplasts for photosynthesis
• also absorb nutrients by diffusion
Title: Apr 29­6:26 AM (5 of 16)
Movement:
• do not move on own; flow with currents
Reproduction:
• asexually by binary fission til too small
• valves separate, each forms new one inside
• sexually by release and union of gametes
• gametes have two flagella so swim + unite
• zygote (fert. egg) that forms devs into adult
Phylum Pyrrophyta
Representative: dinoflagellates
General Features:
• another imp food source for aquatic animals
• protective coat of cellulose plates
• phosphorescent - release a small amt light
• in high numbers, appear as "red tide"
• can produce toxins ~ kill shellfish / poison people
Food Getting:
• have chloroplasts for photosynthesis
• also absorb nutrients by diffusion
Title: Apr 29­6:26 AM (6 of 16)
Movement:
• two flagella - one spins it, one a rudder
Reproduction:
• mainly asexually by binary fission
• sexually in certain circumstances
Plant-like Protists (Algae)
Seaweeds - Multicellular
Title: Apr 29­10:55 PM (7 of 16)
Phylum Chlorophyta (Green Algae)
Representatives:
volvox
spirogyra
ulva (sea lettuce)
General Features:
• the most plant-like algae
• same chlorophyll, cell walls of cellulose, store starch
Movement:
• most live in fresh water and are multicellular
• depends on form: ulva floats, volvox flagella
• leaf like part called thallus (if multicellular)
• show alteration of generations (sexual + asexual stages)
Food Getting:
• have chloroplasts for photosynthesis
• also absorb nutrients by diffusion
Title: Apr 29­6:26 AM (8 of 16)
Reproduction:
• asexually by fragmentation, spores, cell division
• sexually if unfavorable to form zygospore
Phylum Phaeophyta
(Brown Algae)
Phylum Rhodophyta
(Red Algae)
ex. Irish moss, dulse
ex. kelp, rockweed
Note: most imp economically
- source of agar, carrageen
What do they have in common?
• multicellular algae
• photosynthetic autotrophs
• aquatic
• leaflike part called thallus
• anchored to rocks by "root-like" holdfast
• show alternation of generations (asexual and sexual stages in life cycle)
• harvested for use as fertilizer
Title: Apr 29­7:18 AM (9 of 16)
Animal-like Protists (Protozoa)
* separated into phyla based primarily on method of locomotion
Title: Apr 29­7:18 AM (10 of 16)
Phylum Sarcodina
Representative: Amoeba
General Features:
• no cell wall or pellicle; no fixed shape
• cytoplasm: clear ectoplasm, dense endoplasm
• finger-like projections called pseudopods
• live at bottom of fresh water bodies
• contractile vacuole to remove excess water
Food Getting:
• phagocytosis; pseudopods engulf food ~ vacuole
• lysosomes fuse with vacuole, enzymes digest food
Title: Apr 29­6:26 AM (11 of 16)
Movement:
• extends pseudopods in direction wishes to go
• "amoeboid movement"
Reproduction:
• asexually by binary fission
Response to Stimuli:
• light: do not like light, move to pond bottom
Phylum Ciliophora - "Ciliated Protozoa"
Representative: Paramecium
General Features:
• most highly advanced of animal-like protists
• have stiff pellicle, fixed slipper shape
• cytoplasm: clear ectoplasm, dense endoplasm
• definite mouth on oral side
• indent called oral groove (mouth at end of groove)
• contractile vacuole to expel excess water
Movement:
• surface covered with cilia; beat to move
• speed > euglena which > amoeba
Reproduction:
• asexually by binary fission
• sexually by conjugation
Food Getting:
• predators - go out in search for food
Response to Stimuli:
• shoot dart-like trichocysts to paralyze prey (+ defence)
• light: no preference (all water levels)
• use cilia to sweep food into oral groove + mouth
• touch: trichocysts shoot out ~ touch
• food passes through short gullet into food vacuole
• lysosomes fuse with vacuole and enzymes digest food
• undigested material out anal spot
Title: Apr 29­6:26 AM (12 of 16)
Phylum Zoomastigophora - "Flagellated Protozoa"
Representative: trypanosome
General Features:
• aquatic
• picked up by biting insects and spreads disease
• causes African Sleeping Sickness ~ tsetse fly
Title: Apr 29­6:26 AM (13 of 16)
Movement:
• flagellum
• undulating membrane
Phylum Sporozoa
Representative: plasmodium
General Features:
• parasites
• complex life cycles with sporozoite stage
• picked up by biting insects and spread disease
• causes malaria ~ mosquito
Title: Apr 29­6:26 AM (14 of 16)
Movement:
• flagellum
Fungus-like Protists
Phylum Myxomycota - Slime Molds
Phylum Oomycota - Water Molds
General Features:
• tiny slug-like organisms
• creep over damp, decaying plant material
• "streaming blob"
• cytoplasm streams through skeleton-like tubules
• appear ______________ so resemble fungi in this way
Food Getting:
• most are _____________ (feed on dead organic matter)
• engulf food by phagocytosis
Reproduction:
• sexually by formation of _________ (like some fungi)
• these produce haploid spores ~ dry conditions
• unite to form zygote when damp again
Title: Apr 29­7:18 AM (15 of 16)
Book Questions: 7, 9, 11-13, 15, 18-20
Q1: Describe what a slime mold is, why it is named that,
and why it is considered a member of Kingdom Protista.
Q2: List some ways in which the paramecium is more
advanced than other protists.
Title: Apr 29­11:00 PM (16 of 16)