Transcript Protists -the simplest eukaryotes

Protists
-the simplest
eukaryotes
Chapter 22
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I have loved England, dearly and deeply,
Since that first morning, shining and pure,
The white cliffs of Dover I saw rising steeply
Out of the sea that once made her secure.
I had no thought then of husband or lover,
I was a traveler, the guest of a week;
Yet when they pointed 'the white cliffs of Dover',
Startled I found there were tears on my cheek.
I have loved England, and still as a stranger,
Here is my home and I still am alone.
Now in her hour of trial and danger,
Only the English are really her own.
 From The White Cliffs
 of Dover by
 Alice Duer Miller
Characteristics of
Kingdom Protista
 Eukaryotic
 More than one chromosome consisting of
DNA + protein
 Divide through mitosis and meiosis
 Mostly single celled
What they are NOT
 Protists have traditionally been grouped
together more because what they are
NOT than what they ARE.
 They do not fit into any other eukaryotic
kingdom (fungi, plant, animal)
 Through genetic analysis, the
relationship between these organisms is
just becoming clear.
Seven different monophyletic
protistan groups:
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Parabasalids and Diplomonads
Euglenoids and Kinetoplastids
Forams and Radiolarians
Amoebozoans
Red Algae
Green Algae
Stramenophiles and Alveolates (BIG
group!)
Parabasalids and
Diplomonads
 Protozoa- single celled, predatory,
parasitic member of the protistan
kingdom
 Evolutionarily far removed from animals
 Heterotrophic flagellates
 Few mitochondria because of anaerobic
or oxygen poor habitats
Highlighted Speciesparabasalid
Trichomonas vaginalis
* epithelial linings of reproductive
organs
* sucks out nutrients
* can be transmitted to fetus during
childbirth
Highlighted Speciesdiplomonad
Giardia lamblia
* very simple internal structure
* intestinal parasite of humans, cattle
and wild animals
* leaves sucking imprints on inside of
intestine and can result in giardiasis
Euglenoids and
Kinetoplastids
 Flagella!
 Some autotrophic and some
heterotrophic
 Euglenoids have contractile vacuoles
 Kinetoplastids have huge mitochondria
 Most kinetoplastids are parasites
Highlighted SpeciesEuglenoid
Euglena
*photosynthetic
* contractile vacuole
* reproduces through binary fission
Highlighted SpeciesKinetoplastid
Trypanosoma brucei
* causes African sleeping sickness
* Tsetse fly carries T. brucei
* Lodges in brain of host.
* Causes listlessness, drowsiness and
mental deterioration
Foraminiferans and
Radiolarians
 Heterotrophs
 Amoeba-like organisms inside perforated
shells
 Pseudopods extend through hundreds of
holes in the shells
 Plankton- microscopic organisms that
drift or swim weakly in water.
Amoebozoans
 Most closely related to fungi and animals
 Mostly single celled but can display
communal behavior and some cell
differentiation
 No cell wall or shell
 Dynamic changes in shape
 Amoebas and slime molds
Highlighted SpeciesAmoebozoa
Entamoeba histolytica
*can infect people who drink contaminated
water
* live in human intestinal tract and eat
bacteria and epithelial cells
* causes amoebic dysentery
* shares some genes with some
prokaryotes
* kills 100,000 people/year
Amoebozoa
Highlighted SpeciesSlime Molds
Plasmodial slime molds (175 species)
* social amoebas
* found in forests;
on wood or
ground cover
Red Algae (Rhodophyta)
 Live in warm marine climates
 Photoautotrophic and contain phycobilins
(absorb green and blue-green light)
 Although single celled, most show
multicellular growth
 Used as agar, in paints, sushi, dairy
foods
Rhodophyta
Green Algae (Chlorophyta)
 Closest relatives of land plants
 Mostly freshwater aquatic but some
marine
 Single celled and multicellular growth
 Volvox, Ulva, Chlamydomonas
THE BIG GROUP:
the alveolates and
stramenopiles
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Dinoflagellates
Ciliates
Oomycotes
Diatoms
Chrysophytes
Phaeophyta