PROTISTA

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PROTISTA
magic or misfit?
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Domains of Lifefrom a ancestral cell

• Eukarya

• Archea

Eubacteria
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KINGDOM PROTISTA
PLANTS (from algae)
ANIMALS (from protozoa)
PROTISTS
PROKARYOTES
Ancestral cell
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KINGDOM PROTISTA

• Algae
• Protozoans
• Slime Molds
• Water Molds

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PROTIST CHARACTERISTICS

• Eukaryotic
• Aquatic or moist environments
• Unicellular simple colonies colonies showing
  division of labor
• Photosynthetic -- algae
• Heterotrophic -- protozoans

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PROTIST CHARACTERISTICS

• ALL reproduce asexually
• Sexual reproduction occurs in some
• Chlorophyll A -- accessory pigments vary
• Major producers in aquatic ecosystems
• Account for one half of the photosynthetic
  production of organic material in the world
• Account for much of our O2 production

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Algae Divisions

• EUGLENOPHYTA Euglena
• DINOFLAGELLATES (Pyrrophyta)
• BACILLARIOPHYTA Diatoms
• CHRYSOPHYTA Vaucheria
• PHAEOPHYTA Fucus
• RHODOPHYTA Corallina
• CHLOROPHYTA Spirogyra, Odegonium,
• Ulothrix, Volvox

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Division Euglenophyta

• CHLOROPHYLL a and b
• carotenoids, xanthophylls
• 1 TO 3 flagella
• NO cell wall
• PELLICLE
• submembrane protein
• (glucose polymer)
• fresh water habitats
• HAVE STIGMA
• photosensetive eyespot

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Euglena
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PYRROPHYTA-- DINOFLAGELLATES

• Fire Algae
• chlorophyll a c
• carotenoids
• xanthophylls
• 1 lateral 1 posterior flagellum
• produces a spinning motion
• cell wall of cellulose
• marine and freshwater
• Red Tides

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Dinoflagellate
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Dinoflagellate
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One of the dinoflagellates that causes Red Tides
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BACILLARIOPHYTA Diatoms

• chlorophyll a c
• carotenoids
• fucoxanthins
• silicon cell walls

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BACILLARIOPHYTA Diatoms

• two plates (like a Petri dish)
• fresh and marine
• phytoplankton
• formed from diatomaceous earth
• filtering medium insulation
• tooth paste
• silver polish
• all reproduce asexually -- some sexually

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Diatoms
radial symmetry
bilateral symmetry
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CHRYSOPHYTA GOLDEN BROWN ALGAE Vaucheria

• Filamentous coenocytic algae
• (nuclear division not followed by cell wall
  formation)
• Sexual reproduction
• Exhibit sexual dimorphism
• sperm -- antheridia
• ova - oogonium

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CHRYSOPHYTA GOLDEN BROWN ALGAE Vaucheria

• Asexual reproduction
• Club shaped sporangia produce a single large
  zoospore which is multiflagellated
• Zoospore swims around and settles, withdraws
  flagella, germinates, and produces a new filament

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CHLOROPHYTA--GREEN ALGAE

• ancestors of land plants
• chlorophyll a and b
• cell wall of cellulose
• saltwater and freshwater
• associate with fungi to form lichens
• crustose
• foliose
• fruiticose

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CHLOROPHYTA

• Protococcus
• OCCURS AS SINGLE CELLS OR IN SMALL CLUMPS OF
  CELLS
• LIVES ON MOIST BARK OF TREES OR MOIST ROCKS
• REPRODUCES ONLY ASEXUALLY BY CELL DIVISION
• CELLS SPHERICAL WITH A NUCLEUS AND ONE LARGE
  LOBED CHLOROPLAST

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CHLOROPHYTA - Chlorella

• unicellular, spherical
• large cup-shaped chloroplast
• moist soil, fresh and marine
• sexual reproduction only
• form 16 nonmotile spores within parent cell
• parent cell ruptures releasing spores

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CHLOROPHYTA -- Chlamydomonas

• Unicellular with 2 flagella
• cup-shaped chloroplasts with pyrenoids
• has stigma (eyespot)
• freshwater
• Haplontic Life Cycle
• In sexual reproduction, isogametes fuse to form
  2N zygote
• In asexual reproduction, flagellated ZOOSPORES
  are produced inside and released

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CHLAMYDOMONAS

• HAPLONTIC LIFE CYCLE
• IN SEXUAL REPRODUCTION ISOGAMETES FUSE TO FORM A
  2N ZYGOTE.
• IN ASEXUAL REPRODUCTION, FLAGELLATED ZOOSPORES
  ARE PRODUCED INSIDE AND THEN RELEASED.

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Volvox
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CHLOROPHYTA--Volvox

• SPHERICAL COLONY OF HUNDREDS OF FLAGELATTED CELLS
  (colony is motile)
• ASEXUAL REPRODUCTION
• A SURFACE CELL DROPS INSIDE BALL AND BY MITOSIS
  PRODUCES DAUGHTER COLONY.
• PARENT COLONY EVENTUALLY BURSTS TO RELEASE
  DAUGHTER COLONIES.

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CHLOROPHYTA--Volvox

• Sexual Reproduction
• Haploid heterogametes (egg and sperm) from
  within the parent colony.
• Sperm and egg fuse to form a diploid zygote.
• The zygote undergoes meiosis to produce 4 haploid
  nuclei within the zygote. Only one nucleus
  survives. It is released as a spore from the
  zygote and produces a new haploid colony by
  mitosis.

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CHLOROPHYTA--Volvox

• Shows some DIVISION OF LABOR within the colony
• Vegetative cells
• Sperm producing cells
• Egg producing cells
• Daughter colony-producing cells

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Volvox
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Conjugation in Spirogyra
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CHLOROPHYTA--SPIROGYRA

• Filamentous with spiral chloroplast in each cell
• Forms green scum in ponds
• Pyrenoids (sites of starch storage) occur in the
  chloroplast
• Asexual reproduction is by fragmentation of the
  filament.

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CHLOROPHYTA--SPIROGYRA

• Sexual reproduction by conjugation of isogametes
• Two haploid filaments line up.
• Conjugation tube forms between each adjacent pair
  of cells.
• The contents of one cell moves through the
  conjugation tube and fuses with the contents of
  the other diploid zygote.
• Thick-walled zygospore forms from zygote.
• The zygospore overwinters.

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CHLOROPHYTA--SPIROGYRA

• In spring, the zygospore undergoes meiosis to
  produce 4 haploid nuclei. Only one survives and
  divides by mitosis to make a new vegetative
  filament.

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CHLOROPHYTA--Ulothrix

• Filamentous fresh-water alga
• Asexual reproduction is by zoospore production

• Sexual reproduction involves
• flagellated isogametes

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CHLOROPHYTA -- Odegonium

• filamentous fresh-water algae
• some cells of the filament become oogonia
  (egg-producing structures)
• some cells become antheridia (sperm-producing
  structures)
• sexual and asexual reproduction

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PHAEOPHYTA-Brown Algae

• multicellular cold water seaweeds
• Fucoxanthin brown pigment
• food stored as laminarin (future energy source?)
• source of iodine algin used in ice cream

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PHAEOPHYTA-Brown Algae

• most structurally complex algae
• shows tissue differentiation
• body is a flat thin thallus
• exhibit the Diplohaplontic Life Cycle (as do the
  higher plants)

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PHAEOPHYTA Fucus

• Fucus (rockweed) has a flat and dichotomous
  thallus
• found in coastal waters
• holdfasts for anchorage
• air bladders for buoyancy
• receptacles contain conceptacles which produce
  gametes

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RHODOPHYTA--Red Algae

• seaweeds
• phycoerythrin red pigment
• found at great depths
• gelatinous substance coats the thallus source
  of agar

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RHODOPHYTA--Red Algae

• cellulose cell wall
• calcium from seawater is deposited in cell walls
  as calcium carbonate
• contribute to coral reef formation
• complex sexual life cycle

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The Fungus-like Protists

• Slime molds and water molds are protists that are
  fungus-like in some ways but differ from fungi in
  producing motile cells

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Plasmodial Slime Mold
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ACRASIOMYCOTA-- Cellular
Slime Molds

• Cellular slime molds exist as individual amoeboid
  cells most of the time, but there is a phase in
  the life cycle when fungus-like spores are
  produced.

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Division Acrasiomycota (fungus-like protists)
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Cellular Slime Mold Sporangia
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OOMYCOTA-- water molds

• water molds resemble fungi in having a
  filamentous body
• most are saprotrophic
• carry on external digestion if dead organic
  material is available
• absorb the resulting nutrients across the plasma
  membrane
• molds differ from fungi in producing motile
  diploid zoospores

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Division Oomycota (water molds)
Saprolegnia
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Division Oomycota-- water molds

• Some parasitize fishes forming furry growths on
  their gills. Another parasitic water mold caused
  the 1840s Potato Famine in Ireland

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Protozoan