Protozoans
Algae
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mostly unicellular, some are multicellular
(algae)
can be heterotrophic or autotrophic
most live in water (though some live in moist
soil or even the human body)
ALL are eukaryotic (have a nucleus)
A protist is any organism that is not a plant,
animal or fungus
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Classification of Protists
◦ how they obtain nutrition
◦ how they move
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Animallike Protists - also called protozoa
(means "first animal") - heterotrophs
Plantlike Protists - also called algae autotrophs
Funguslike Protists - heterotrophs,
decomposers, external digestion
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Four Phyla of Animallike Protists
Classified by how they move
◦ Zooflagellates - flagella
◦ Sarcodines - extensions of
cytoplasm (pseudopodia)
◦ Ciliates - cilia
◦ Sporozoans - do not move:
parasitic
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move using one or two flagella
absorb food across membrane
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moves using pseudopodia ( "false feet" ),
which are like extensions of the cytoplasm
--ameboid movement
ingests food by surrounding and engulfing
food (endocytosis), creating a food vacuole
reproducing by binary fission (mitosis)
 contractile vacuole - removes excess
water
 can cause amebic dysentery in
humans - diarrhea and stomach upset
from drinking contaminated water
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Ameboid movement: cytoplasmic
streaming
move using cilia
 has two nuclei:
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◦ Macronucleus controls life processes
◦ Micronucleus used in reproduction only
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Reproduces asexually (binary fission)
or sexually (conjugation)
Conjugation: DNA is exchanged
through the mouth pore
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food is gathered through the :mouth pore
Where it moves thru a gullet,
At the end of the gullet a food vacuole is
formed.
Food that is undigessted is released thru
the anal pore
The indentation where the mouth pore is
located is called the oral grove.
contractile vacuole removes excess
water
 exhibits avoidance behavior
 outer membrane -pellicle- is rigid and
paramecia are always the same shape,
like a shoe
 Just inside the pellicle are trichocysts
◦ Threadlike organelles used for defense
See them swim
See them eat
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do not move on their own
Parasitic
Malaria is a sporozoan, infects the liver and
blood…. We will talk more about this later in
the presentation.
an organism that lives on or in a host
organism and causes harm to that organism
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an organism that can carry a parasite, and is
responsible for infecting other organisms
(host) with that parasite.
Vectors themselves are not harmful, but in
the battle against human disease, controlling
the vector can control the transmission of
parasites.
 Protist:
Plasmodium
 Vector: Anopholes Mosquito
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According to the World Health Organization,
300-500 million cases of malaria occur each
year
Malaria results in 1.5-2.7 million deaths per
year (much more than AIDS)
Most cases occur in Africa and South America
Symptoms include fever, headache, vomitting
and other flu-like symptoms
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The protist lives inside the bloodstream,
eventually clogging capillaries and destroying
blood cells, which will lead to death if not
treated
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Protist: Trypanosoma
Vector: Tse Tse Fly
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Occurs mostly in sub-saharan Africa
Symptoms include fever, headaches, pain in
joints -followed by a phase when the parasite
infects the central nervous system, causing
confusion, lack of coordination, and
uncontrolled sleepiness.
Without treatment, the host will die .
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Protist: Giardia
Transmission: Drinking contaminated water
(usually outdoor streams and other untreated
water)
Symptoms: Severe diarrhea and vomitting, the
protist takes up residence in the digestive
tract.
Toxoplasma gondii
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considered to be the third leading cause of
death attributed to foodborne illness in the
United States
infects most species of warm blooded
animals, including humans
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Cryptsporidium - this protist was responsible
for a major health crisis in Detroit when the
city's drinking water became contaminated
Amebic Dysentery - also known as
Montezuma's Revenge, travellers often
contract this in other countries (causes
diarrhea)
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contain chlorophyll and carry out
photosynthesis
commonly called algae
Four Phyla: Euglenophytes, Chrysophytes,
Diatoms, Dinoflagellates
accessory pigments help absorb light, give
algae a variety of colors
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live in water (such as quiet ponds or
puddles)
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have flagella for movement
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◦ Anterior or front
use chlorplasts for photosynthesis,
but can turn into heterotrophs if they
are kept in the dark
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has an eyespot used for sensing light
and dark
◦ Located near the flagella
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pellicle - like a cell wall, helps
maintain their shapes
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Contractile vacuole for removing xs
water.
DIATOMS:
Cell walls made of silicon
dioxide which give the a glass
like appearance
Diatomaceous earth: the cell
walls of diatoms after the cell
dies.
Dinoflagellates
Often have two flagella
luminescent
Spirogyra
live in water,
named after a spiral shaped chloroplast
autotrophic
Cell Walls: cellulose
Commonly called sea weed
 Live in deep salt water
 Are used by humans to help make ice
cream and hair conditioner
 Are eaten in some Asian cultures
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Commonly called sea weed
Have large leaf-like structures called blades
Have air-filled sacs called air bladders
Have root-like structure called holdfast
Are used by humans to help make pudding
and salad dressing
Fungus-like protists are
heterotrophswith cell walls.
They also reproduce by forming
spores.
All fungus-like protists are able to
move at some point in their lives.
There are essentially three types of
fungus-like protists:
water molds
downy mildews
slime molds.
Water Molds
Live in water or moist environments
Look like tiny threads with a fuzzy covering
Attack food such as potatoes, cabbage, and corn
and can destroy whole crops
Slime Molds
Live in moist soil and on decaying
plants and trees
Very colorful
Move by forming pseudopods
Feed on bacteria and other
microorganisms