Protists

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Protists
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Protists are the Most Diverse of all Eukaryotes

• Eukaryotes that are not plants, animals or fungi
  are classified as protists

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Protists are the Most Diverse of all Eukaryotes

• Eukaryotes that are not plants, animals or fungi
  are classified as protists
• Most protists are unicellular and free living
  (non-parasitic)

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Protists are the Most Diverse of all Eukaryotes

• Eukaryotes that are not plants, animals or fungi
  are classified as protists
• Most protists are unicellular and free living
  (non-parasitic)
• Some protists are colonial organisms. This means
  that they consist of many similar or identical
  cells

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Protists are the Most Diverse of all Eukaryotes

• Eukaryotes that are not plants, animals or fungi
  are classified as protists
• Most protists are unicellular and free living
  (non-parasitic)
• Some protists are colonial organisms. This means
  that they consist of many similar or identical
  cells
• Some protists, such as seaweed are multicellular
  and have relatively complex bodies

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Protist Structure

• Protists have a typical eukaryotic cell
  structure, including a nucleus, internal
  membrane-bound organelles

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The Future of Protists

• Many biologist believe that with sufficient data
  the protist kingdom will eventually be broken up
  into several kingdoms within the Eukarya domain

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Protists as the Most Complex Cell

• What does this mean?

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Protists as the Most Complex Cell

• What does this mean?
• Being mostly unicellular, protists are considered
  the simplest form of eukaryotic organisms

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Protists as the Most Complex Cell

• What does this mean?
• Being mostly unicellular, protists are considered
  the simplest form of eukaryotic organisms
• While humans are more complex than protists,
  human cells are in many ways, less complex than
  protists

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Protists as the Most Complex Cell

• What does this mean?
• Being mostly unicellular, protists are considered
  the simplest form of eukaryotic organisms
• While humans are more complex than protists,
  human cells are in many ways, less complex than
  protists
• Most human cells are highly specialized and carry
  out specific limited function

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Protists as the Most Complex Cell

• Protists cells must carry out ALL of lifes
  functions if they are to survive

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Protists as the Most Complex Cell

• Protists cells must carry out ALL of lifes
  functions if they are to survive
• They must find food, digest it, utilize the
  nutrients, they must avoid predators, they need
  to reproduce, manufacture proteins, package and
  ship them, they must produce energy and dispose
  of waste

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Grouping Protists by Nutrition

• Protists are grouped as animal-like protists,
  fungus-like protists and plant-like protists

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Grouping Protists by Nutrition

• Protists are grouped as animal-like protists,
  fungus-like protists and plant-like protists
• Animal-like protists are called protozoans

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Grouping Protists by Nutrition

• Protists are grouped as animal-like protists,
  fungus-like protists and plant-like protists
• Animal-like protists are called protozoans
• Protozoans are heterotrophs that ingest food

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Grouping Protists by Nutrition

• Protists are grouped as animal-like protists,
  fungus-like protists and plant-like protists
• Animal-like protists are called protozoans
• Protozoans are heterotrophs that ingest food
• Fungus-like protists are also heterotrophs, but
  they mostly feed on decaying organic matter

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Grouping Protists by Nutrition

• Plant-like protists are called algae, they are
  autotrophs and make there food using
  photosynthesis just like plants do

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Motility in Protozoans

• Protozoans move by one of three different
  methods Flagella, pseudopods and cilia

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Motility in Protozoans

• Zooflagellates move by means of one or more
  flagella (long, thin, whip-like cellular
  projections)
• Zooflagellates generally reproduce asexually by
  binary fission
• Examples of zooflagellates are euglenia, giardia
  (causes diarrhea) and trypanosoma (causes African
  sleeping sickness)

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Motility in Protozoans

• Protozoans with pseudopods
• Pseudopodia are temporary extensions of the
  cytoplasm and the plasma membrane
• The cell moves in the direction of the growing
  pseudopod
• Amoeba are examples of protists that utilize
  pseudopods

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Motility in Protozoans

• Ciliates are a diverse group of protozoans named
  for their use of hair-like cilia to move and feed
• Cilia are much shorter than flagella and much
  more numerous
• Paramecium and stentor are common ciliates
• Ciliates reproduce both asexually and sexually
  through conjugation

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Non-motile Protists

• A fourth group of non-motile protists exists
• These protists are called apicomplexans
• Apicomplexans have complex life cycles
• The most well known apicomplexan is plasmodium,
  the protist that causes Malaria (remember Malaria
  IS NOT caused by mosquitos)

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