Ch. 20

 They are eukaryotes that don’t fit in any other kingdom… ◦ Most are unicellular (but not all) ◦ They are heterotrophs, autotrophs or both ◦ They are sessile or motile ◦ They live in aquatic/moist environments

 1.5 billion years ago protists evolved  They were the first eukaryotes (endosymbiotic theory)

 There is no consensus regarding their classification; one way is based on their mode of nutrition: ◦ Animallike – heterotrophs ◦ Plantlike – autotrophs ◦ Funguslike – decomposers/parasites This system does not reflect evolutionary relationships.

 Zooflagellates – flagella  Sarcodines – pseudopods  Ciliates – cilia  Sporozoans – parasites

 Unicellular algae ◦ Euglenoids ◦ Chrysophytes ◦ Diatoms ◦ dinoflagellates

 Multicellular algae ◦ Red, brown and green

 Slime molds and water molds