Plantlike Protists: Unicellular Algae

  • contain chlorophyll and carry out photosynthesis
  • commonly called algae
  • four phyla: euglenophytes, chrysophytes, diatoms, dinoflagellates
  • accessory pigments help absorb light, give algae a variety of colors

Euglenophytes

Euglena (See Euglena Coloring Sheet )

live in water
have 2 flagella for movement
use chlorplasts for photosynthesis, but can turn into heterotrophs if they are kept in the dark
has an eyespot used for sensing light and dark
pellicle - like a cell wall, helps maintain their shapes

 

Chrysophytes
yellow-green algae, "golden plants"

Diatoms
produce thin cell walls of silicon, main component of glass

Dinoflagellates
Often have two flagella
luminescent

Ecology of Unicellular Algae

  • make up the base of aquatic food chains
  • phytoplankton makes up half of the photosynthesis that occurs on earth (oxygen)
  • can cause Red Tides - algal blooms - which are toxic

Plantlike Protists: Red, Brown, Green Algae

Green Algae: Phylum Chlorophyta

Unicellular green algae, Colonial (volvox), Multicellular (ulva, sea lettuce)

Spirogyra

live in water, multicellular
named after a spiral shaped chloroplast
autotrophic

 

Funguslike Protists

  • heterotrophs, decomposers
  • called slime molds and water molds
  • water molds responsible for the Irish Great Potato Famine