Transcript Protists

Protist Kingdom
What is a Protist?
~ Diverse group of Eukaryotic organisms that exist as
independent cells or as a colony of cells.
~ Do not fall into the category of animals, plants, or
fungi.
~ They are more complex than bacteria because
they have a nucleus.
~ They are bigger than bacteria.
What the following Clip
http://www.youtube.com/watch?v=UOfY26qdbU0
If you tube does not work
http://www.monkeysee.com/video_clips/24762what-is-a-protist
Animal-like Protists
Known as Protozoans:
There are 4 types
named based on the way they live and move
Amoeba eating paramecia
Pseudopod:
An amoeba uses pseudopods to move
and feed. Pseudopods form when th cell
membrane bulges and cytoplasm flows
into the bulge.
Cytoplasm
Nucleus:
The nucleus controls the cell’s
functions and is involved in
reproduction. Amoebas usually
reproduce by binary fission
Food Vacuole:
When the ends of two pseudopods
fuse, they form a food vacuole. Food is
broken down inside the food vacuole in
the cytoplasm
Contractile Vacuole:
The contractile vacuole collects
excess water from the
cytoplasm and expels it from
the cell
Group 1: Protozoans with Pseudopods
Amoeba
~ Belong to group called Sarcodines
~ Sarcodines move and feed by forming pseudopods
~ pseudopod: means false foot
~ Amoeba: temporary bulge of the cell membrane that fills with
cytoplasm forming the false foot, allowing it to push outward in one
location. Cytoplasm fills the foot and the rest of the organism follows.
~ Amoeba’s have a slight problem. They allow water to pass through
their cell membrane. If they allow too much through the cell will
explode. They have a contractile vacuole that collects the extra water
and expels it from the cell.
~ Amoebas eat algae, bacteria, plant cells, and microscopic protozoa
and metazoa.
~Amoebas live in fresh water (like puddles and ponds), in salt water, in
wet soil, and in animals (including people).
~ Reproduce by binary fission (asexual)
Ameba eating using pseudopod
Food Vacuole:
Forms and pinches off from the oral
groove. It moves into the cytoplasm
inside the vacuol, the food is broken
down and then distriubted
Oral Groove:
Funnel-like indentation lined
with cilia. The cilia move
water containing food into the
vacuole that forms at the end
of the oral groove.
Cilia:
Thousands of
cilia project
through the
pellicle. The
beating cilia
enable a
paramecium to
move smoothly
in one direction
Large Nucleus
Group 2 Protozoan with Cilia
Paramecium
~ Group called ciliates
~ this group has cilia, hair like projections from cells that move
with a wavelike pattern.
~ Cilia used to move, obtain food, and sense the environment.
~ More complex cell than Amoeba, as they have a Nucleus and a
Nucleolus.
~ Reproduce asexually – binary fission; some occasions may
reproduce sexually through conjugation
~ Found in freshwater environments such as lakes, ponds and
puddles.
~ Paramecium eat algae, bacteria, other protozoans, dead
plant and animal matter, and other tiny animals.
Paramecium Expelling Excess Water
Group 3: Protozoan with Flagella
Zooflagellates
~ Animal like protists that use flagella to move
~ Have one to eight long whip-like flagella that
help them move.
Symbiotic relationship :
mutualism in which both
species benefits
Zooflagettates digest wood that the
termite eats, producing sugars for
themselves and for the termite
Giardia: zooflagellate is a
parasite in humans.
Wild animals such as beaver,
deposit Giardia into
freshwater
When humans drink the water
the Giardia attach to intestinal
walls feeding and reproducing
Group 4: Other Protozoans
~ Sporozoans classified by the way they live
instead of the way they move.
~ Parasictic feeding on the cells and body fluids
of their hosts.
~ They may move by flagella, catching a ride on
a host, or even through slime that it produces.
Plasmodium: sporozoan that
causes malaria
Plasmodium: must be in the human taken in
by blood by the mosquito into another
human
Fungus-like Protist
~ Like fungi, fungus like protists are heterotrophs, have cell
walls, and use spores to reproduce.
~ Unlike fungus all fungus-like protists are able to move at some
point in their lives.
3 Types
Water molds, downy mildews, slime molds
Water Molds & Downy Mildews
~ Live in water or moist places
~ Parasite that grows on living organisms
~ Grow as tiny threads that look like a
fuzzy covering
~ Attack life within water
~ Attack food crops like potatoes,
cabbages, corn and grapes.
Fish attacked by water mold
Water mold destroyed the Irish
potato crops in 1845-1846
Los of these crops led to a famine
that resulted in the deaths of over
one million Irish people
Slime Mold
~ Live in moist soil and on decaying plants and
trees.
~ Beautifully colored (many bright yellow)
~ Glistening bodies creep over fallen logs and
dead leaves on shady, moist forest floors.
~ Move in an amebalike way by forming
pseudopods and oozing along the surfaces of
decaying materials.
~ Feed on bacteria and other microorganisms
Yellow Slime Mold on Dead Wood