The Protists

Kingdom Protista Eukaryotic Most are single celled, but may be in colonies. A few are considered multicellular, but do not show specialization. Live in moist habitats Protists are extremely diverse. They may be plant-like, animal-like, fungus-like or anywhere in between. Mini Question

Questions 1. How is a eukaryotic cell different from a prokaryotic cell? 2. Why are protists considered eukaryotic? 3. Euglena are protists that have flagella and chloroplasts. They are both heterotrophic and autotrophic. Why would this present a problem to a taxonomist using a classification system with only plant and animal kingdoms?

Protista: Reproduction Sexual and/or Asexual reproduction depending on the species Some have complex life cycles involving other organisms Ex. Plasmodium (which causes malaria)

Plant-like Protists Green Algae – single celled Brown algae – kelp/seaweed Red algae – single celled, causes red tides. Can cause major fish-kills. Diatoms – secrete a silica shell. The shells collect over time. Diatomacheous earth is used in toothpaste!

Plant/Animal Like Protists Euglena Moves with a whip-like flagellum Has chloroplasts – can do photosynthesis May also hunt if necessary Has a red eye spot that can sense light Contractile vacuole controls water pressure

Phylum Sarcodina – Amoeba Animal Like Protists Phylum Sarcodina – Amoeba Moves with Amoeboid motion using a psuedopod (false foot) Fierce Hunter – eats through endocytosis Has a contractile vacuole

Animal Like Protists Phylum Ciliophora – paramecium Move with cilia – small hairs along the body. Very fast hunters Have an oral grove and anal pore Also have a contractile vacuole

Giardia – lives in freshwater all over the world. Parasitic Protists Giardia – lives in freshwater all over the world. Causes diarrhea, food sensitivity, nausea, exhaustion. Very common in animals

Parasitic Protists Plasmodium Causes malaria Lives in the red blood cells and liver Breaks apart blood cells as it reproduces Transmitted to new hosts by a mosquito vector (in between organism) Causes fevers, headaches and death