Chapter 18: Protists

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Chapter 18 Protists

• Virus
• Monera
• Protista

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Taxonomic thinking
Animals
Plants
Fungi
Protists
Monera
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Phylogenetic Thinking
EUKARYA
ARCHAEA
BACTERIA
Animals
Plants
Protists
Fungi
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Prokaryotes vs Eukaryotes
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Prokaryotes

• Kingdoms Monera (bacteria)
• cell membrane and cell wall.
• Prokaryotic cells lack nucleus and membrane
  bound "organelles,
• Some have flagella for locomotion or hair like
  pili for adhesion.
• Cells multiple shapes cocci (round), baccilli
  (rods), and spirilla (helical cells).
• Note prokaryotes will not have
  microtubules in flagella

BACK
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Eukaryotes

• Cells have nuclei and membrane-bound organelles

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What are Protists?
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What are Protists?

• Greek word meaning first
• First kingdom of eukaryotes
• Unicellular
• Nuclei
• Organelles
• Reproduce by mitosis
• Multiple chromosomes
• Protists often have a very complicated internal
  structure a single cell must do all the
  functions that we have many different cell types
  to do.

Increasing in diversity
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All protists live in water, or moist soil, or
moist interiors of other organisms
Surface watersteem with microscopic protists
In some near-shore areas, gigantic protists form
underwater forests
Protists areparticularlyabundant intidal
habitats
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Classification

• 115,000 species
• Major debate regarding how they should be
  classified
• animal-like zooplankton or protozoans
• plant-like phytoplankton
• ?

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Increasing diversity

• Protists share characteristics with more then one
  multicellular kingdom
• - plant-like
• -fungus-like
• -animal-like forms

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Animal-like Protists
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Plants-like Protists
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Fungus-like Protists (slime molds)
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Protists exhibit wide variation in morphology,
size, and nutritional strategies
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Protists are divided into groups largely based on
locomotion

• 1) Sarcodines
• Blob-like asymmetrical
• Assume infinite variety of shapes
• Ex. Amoebae
• 2) Flagellates
• Ex. Euglena
• 3) Ciliates
• Ex. Paramecium
• 4) Sporozoans
• Have no organs for locomotion in adult form
• Many are parasitic

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Figure 27.1
PROTISTS
Kinetoplastids
Diplomonads
Slime molds
Brown algae
Parabasalids
Fungi
Amoebae
Dinoflagellates
Red algae
BACTERIA
Animals
Ciliates
Oomycetes
Green algae
ARCHAEA
Euglenids
Diatoms
Land plants
Apicomplexa
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We will observe the following four

• Ciliates
• 1) Paramecium caudatum
• 2) Stentor coeruleus
• Sarcodines
• 3) Amoeba proteus
• Flagellates
• 4) Euglena gracili

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Paramecium

• Live in FRESH water
• Osmosis causes water to move into the paramecium
• Contractile vacuole collects the extra water so
  that the paramecium doesnt lyse
• Covered in cilia used for locomotion and for
  directing food into the oral cavity
• Most are free-living (not parasites)

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Amoeba

• Sizeable amount of cytoplasm
• Cytoplasmic streaming pushes on the cell membrane
  resembling arms
• A clear nucleus
• False foot pseudopods to move and capture prey
• Feeding endocytosis surround food creates a
  food vacuole.
• Ameoba reproduce by binary fission

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Euglena

• Plant-like
• Long flagellum excellent swimmers
• A red-spot (photoreceptor) helps euglena detect
  sunlight so its chloroplasts can make glucose
  using photosynthesis

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Stentor coeruleus (S.coeruleus)

• trumpet-shaped or cylindrical highly contractile
• contractile vacuole anterior-left fresh water