PROTISTS

YOU MUST KNOW… SOME DON’T CLASSIFY PROTISTS AS A KINGDOM HOW CHLOROPLASTS AND MITOCHONDRIA EVOLVED THROUGH ENDOSYMBIOSIS

CONCEPT 28.1 MOST EUKARYOTES ARE SINGLE-CELLED ORGANISMS

PROTISTS ARE… EUKARYOTES THAT ARE NEITHER PLANTS, ANIMALS, NOR FUNGI PROTISTS ARE PARAPHYLETIC – MANY ARE MORE CLOSELY RELATED TO PLANTS, FUNGI, OR ANIMALS THAN TO OTHER PROTISTS

PROTISTS VARY IN STRUCTURE AND FUNCTION MORE THAN ANY OTHER GROUP OF EUKARYOTES COMMONALITIES ARE: MOST ARE UNICELLULAR MOST USE AEROBIC METABOLISM AND HAVE MITOCHONDRIA

MITOCHONDRIA AND CHLOROPLASTS EVOLVED THROUGH ENDOSYMBIOSIS THEY WERE ORIGINALLY UNICELLULAR ORGANISMS ENGULFED BY OTHER CELLS THAT ULTIMATELY BECAME ORGANELLES IN THE HOST CELLS

3 CATEGORIES PLANT-LIKE PROTISTS – PHOTOSYNTHETIC ANIMAL-LIKE PROTISTS – INGEST FUNGUS-LIKE PROTISTS – ABSORB

EXAMPLES GIARDIA EUGLENA DINOFLAGELLATES PLASMODIUM (MALARIA) CILIATES (PARAMECIUM) AMOEBA DIATOMS ALGAE SLIME MOLDS