Protists

• Protists are classified under the Kingdom Protista
• Protists include mostly unicellular organisms that do not fit into any other Kingdom
• 200 000 known species, protists have the greatest diversity
• Three Groups of Protista

  1. Protozoa
  2. Algae
  3. Slime and Water Moulds
• Protozoa, Amoeba

  
• Protozoa, Paramecium

  
• Protozoa

  Animal-like, unicellular, heterotrophic

  e.g microscopic, unicellular, Amoeba, Paramecium
• Algae

  plant-like, uni- or multicellular, autotrophic

  e.g macroscopic, red brown, green algae

  Euglena, Dinoflagellates, Diatoms
• Spirogyra (green algae)

  
• Euglena algae

  
• Dinoflagellates algae

  
• Diatoms algae

  
• Slime and Water Moulds


  fungus-like, multicellular, heterotrophic organisms

  
• Protists have true nuclei, are therefor Eukaryotic
• Some are unicellular and microscopically small, others are simple multicellular organisms that show a primitive level of differentiation
• Algae are autotrophic and produce their own organic nutrients

  Others are heterotrophic and are dependent of other organisms for food
• Reproduction is mostly asexual and occurs by binary fission, where a single cell divides into two cells with identical genetic material, some algae to reproduce sexually
• Protists live in any environment where water occurs as most protists are aquatic