PROTISTS
CHARACTERISTICS
• https://www.youtube.com/watch?v=8deF3Rw4ti4
• Kingdom: Protista (“the very first”
• A Protist is any organism that is not a plant, animal or fungus.
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Mostly unicellular (some multicellular – (algae))
• Heterotrophic or autotrophic
• Most live in water (but some live in moist soil or even the
human body)
• Eukaryotic (have a nucleus)
• Classified by
• How they obtain nutrients
• How they move.
ANIMAL-LIKE PROTISTS
• Characteristics:
• Called “protozoans” (first animals)
• Heterotrophs
• Classified by how they move
• Examples:
• 1. Zooflagellates (phylum Zoomastigina)
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Swim using flagella (1 or 2)
Absorb food through cell membrane
Live in lakes or streams\
Ex” Giardia
ANIMAL-LIKE PROTISTS
• 2. Sarcodines (Phylum Sarcodina)
• Move with extensions of cytoplasm called pseudopods
• Ex: Amoeba and Foramineferans
ANIMAL-LIKE PROTISTS
• 3. Ciliates (Phylum Ciliophora)
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Have cilia (short, hair-like projections for feeding and movement)
Live in fresh and salt water
Many are free living (not parasites)
Ex: Paramecium (sweeps particles into its gullet
ANIMAL-LIKE PROTISTS
• 4. Sporozoans (phylum Sporozoa)
• Do not move on their own (parasitic)
• Ex: Malaria
PLANT-LIKE PROTISTS
• Characteristics
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Many contain the green pigment chlorophyll and carry out photosynthesis
Many are highly motile and able to move freely
Commonly called algae
Classified according to their pigments and how they store food.
PLANT-LIKE PROTISTS
• 1. Euglenas (phylum Euglenophyta)
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Have characteristics of both plants and animals
Have 2 flagella and no cell wall
Have chloroplasts
Found in ponds or lakes
Eyespot that responds to light
PLANT-LIKE PROTISTS
• 2. Chrysophytes (phylum Chrysophyta) – “golden plants”
• Includes yellow-green algae and golden-brown algae
• Cell walls made of pectin instead of cellulose
• Store food in the form of oil instead of starch
PLANT-LIKE PROTISTS
• 3. Diatoms – (Phylum Bacillariophyta)
• Produce thin delicate cell walls rich in silicon (main component of glass)
PLANT-LIKE PROTISTS
• 4. Dinoflagellates (Phylum Pyrrophyta) – “fire plants”
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½ are photosynthetic and ½ are heterotrophic
Found in fresh and salt water
Have red pigment and move with 2 flagella
Many are luminescent and give off blue light
Can produce red-tides
PLANT-LIKE PROTISTS
• Red Algae (Phylum Rhodophyta) – “red plants”
• Contain chlorophyll a and reddish accessory pigment – phycobilins –
which absorb blue light and allows to live in deeper waters.
• Found in waters from polar regions to tropics
• Play role in formation of coral reefs
• Lack flagella
• Ex: Irish Moss (gives toothpaste and pudding its smoothness and wrappers
in sushi rolls)
PLANT-LIKE ALGAE
• Brown Algae – (phylum Phaeophyta) – “dusky plants”
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Multicellular (largest and most complex of the algae
Most marine found in cool, shallow, coastal waters of temperate or arctic
Largest – giant kelp (ex: Sargassam)
Most common – Fucus (rockweed)
Used in ice cream!
PLANT-LIKE PROTISTS
• 7. Green Algae (phylum Chlorophyta) – “green plants
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Similar to plants in photosynthetic pigments and cell wall composition
Store food in form of starch (like plants)
Found in fresh and salt waters and moist areas on land.
Most as single cells; others as colonies
FUNGUS-LIKE PROTISTS
• Characteristics
• Features of both protists and fungi
• Grown in damp, nutrient-rich environments and absorb
food through cell membranes.
• Heterotrophs that absorb nutrients from dead or decaying
organic matter (decomposers)
• Have centrioles
• Lack chitin (cell walls of true fungi)
FUNGUS-LIKE PROTISTS
• 1. Slime Molds
• Phylum Acrasiomycota (cellular slime molds)
• Phylum Myxomycota (acellular slime molds)
• Found in damp soil and on rotting wood
• Decomposers (recycle organic material)
• 2 life stages
• 1. flat, sideways mass and moves like amoeba
• 2. upright similar to fungus and produces spores
FUNGUS-LIKE PROTIST
• 2. Water Molds
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Phylum Oomycota (water molds, downy mildews, white rusts)
Thrive on dead or decaying organic matter in water
Some are parasitic to plants and animals
Ex: water molds attacked potato crop in Ireland (1840’s – famine killed
over a million people)
DISEASES AND ECOLOGICAL
IMPORTANCE
• Ecological Importance
• 1. Fungus-like
• Decomposers (recyclers of organic material)
• 2. Plant-Like
• Diatoms – cell walls of silicon (component of glass)
• Red algae – coral reef formation; wrappers in sushi; Irish moss for
toothpaste and pudding
• Brown algae – ice cream
DISEASES – ANIMAL LIKE
1. Animal Like Protists:
• Malaria
• Caused by sporozoan Plasmodium carried by female mosquito in saliva
bite.
• It travels through bloodstream and infects liver and blood cells.
DISEASES – ANIMAL LIKE
• African Sleeping Sickness
• Caused by zooflagellates of genus Trypanosoma spread by
bite of tsetse fly. It destroys blood cells and infects other
tissues (fever, chills, rashes, and infects nerve cells – lose
consciousness and lapse into deep, sometimes fatal, sleep.
DISEASES – ANIMAL LIKE
• Amoebic Dysentery
• Caused by parasitic protist Entamoeba that live in the intestine and absorb
food from the host. Also attack wall of intestine destroying parts and
causing severe bleeding. Found where sanitation is poor in food and
water.
DISEASES – FUNGUS LIKE
• Plant diseases (mildews and blights of grapes and
tomatoes)
• Potato famine of Ireland in
1845
DISEASES – PLANT LIKE
• Dinoflagellates
• Can produce red tide – contain toxin that becomes
concentrated in tissue of filter feeders (clams and oysters) –
could cause illness, paralysis or death to human who eat
clams.