Transcript Plant-like Protists

Protists
• The kingdom protista is a diverse group
that may include more than 200,000
species.
• A protist is any organism that is not a plant
an animal, a fungus, or
a prokaryote.
• Protists were the first eukaryotes on Earth
1.5 billion years ago.
• Endosymbiosis? What's that?
• Protists are so diverse that many
biologists suggest that they should be
broken up into several kingdoms.
• This idea is supported by recent studies of
protist DNA indicating that different groups
of protists evolved independently from
archaebacteria.
Animal-like protists: Protozoans (zooflagellates,
Sarcodines, Cilliates, Sporozoans)
• ZOOFLAGELLATES
• Absorb food through cell membrane. Many live
in lakes and streams. Others in the bodies of
other organisms. Most reproduce asexually by
mitosis.
• Few have a sexual life cycle. Motility is possible
due to a flagellum. Some are parasitic:
Trypanosoma ~ African sleeping sickness.
• SARCODINES
• Motility possible via cytoplasmic
projections called pseudopods. These
structures are also used for feeding. The
most common is the amoeba.
• SARCODINES
• Foraminiferans ~ calcium carbonate
(CaCO3) / Heliozoans ~ silica (SiO2)
Heliozoan
• CILIATES
• Ciliates are found in both fresh and salt
water. Most are free living. Motility via
cilia, short hair like projections. Most
common ciliate: Paramecium ~
the image on the homepage of the
website.
Animal-like protists: Protozoans (zooflagellates,
Sarcodines, Cilliates, Sporozoans)
• SPOROZOANS
• This group of protist is parasitic. Reproduce via sporozoites. Most
common: Plasmodium which causes malaria.
• Many play an important role in the world. Some live symbiotically
with other organisms, others recycle nutrients by breaking down
organic matter.
• Some serve as food for other small organisms. Some are very
beneficial to other organisms like Trichonympha, a zooflagellate that
lives in the digestive
system of termites. These protist break down the cellulose in wood!
Not the termite...
Plant-like Protists: Unicellular algae
• EUGLENOPHYTES
Plant like protists that have two flagella but no
cell wall. Photosynthetic and heterotrophic /
Eyespot (red)
• CHRYSOPHYTES (golden plant)
Yellow-green algae and the golden-brown algae.
• DIATOMS
Diatoms produce thin, delicate cell walls
rich in silicon (Si) - the main component of
glass.
• DINOFLAGELLATES
Half are photosynthetic and half
heterotrophic. Many are luminescent, and
when agitated by sudden movement in the
water, give-off light.
Plant-like Protists: Unicellular algae
• Phytoplankton is the group of small, photosynthetic organisms found
near the surface of the ocean. About half of the photosynthesis that
occurs on Earth
is carried out by phytoplankton. Primary producers too...
• Algal Blooms ~ absorb organic material directly and use it for
food. Grow rapidly in waters where sewage is discharged. Play
important role in recycling
these wastes. When waste is excessive, they grow to great masses
(blooms). These blooms deplete the water of oxygen when they
consume all the
nutrients and die. This disrupts the equilibrium of the ecosystem
causes fish and invertebrate die-offs. (red tide)
• Can accumulate in certain shell-fish which in turn are eaten by
humans causing illness, even death.
Plantlike Protists: Red, Brown, and Green
Algae
• Beach at low tide?
• RED ALGAE (Rhodophyta ~ red plants)
Able to live at great depths due to their ability to harvest
light energy. (Chrorophyll a)
• BROWN ALGAE (Phaeophyta ~ dusky plants)
The largest of the algae. Chlorophyll a, c and brown
pigments. Giant kelp - 60 meters in length.
• GREEN ALGAE (Chlorophyta ~ green plants)
Share many characteristics with plants including
photosynthetic pigments and cell wall composition.
Closely related to mosses. Marine & freshwater.
Unicellular - Colonial multicellular
Human uses:
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50% of O2 production
Sushi
Plastics
Waxes
Transistors
Deodorants
Paints
Lubricants
Artificial wood
Agar
The End
Vocabulary / Home learning assignment
1. Protist
2. Pseudopoda
3. Amoeboid movement
4. Food vacuole
5. Cilium
6. Macronucleus
7. Micronucleus
8. Gullet
9. Contractile vacuole
10.Conjugation
11.Eyespot
12.Phytoplankton
13.Spore
1st period:
~ read pages 350 – 368
and observe all
pictures!!!
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2nd thru 6th periods:
~ read pages 356 – 368
and observe all
pictures!!!