Kingdom Protista Biology 11 S.Dosman

Evolution of Protists Fossils show that protists began appearing about 1.5 billion years ago, more recent than bacteria. Their evolution involved the development of a membrane bound nucleus and the development of organelles such as ribosomes, lysosomes and mitochondria. These are the first eukaryotic cells.

Basic Characterisitcs All organisms within kingdom Protista share the following basic characteristics: Mostly microscopic and unicellular with some colonial or multicellular All eukaryotic (belong to Domain Eukarya) Can be heterotrophic or autotrophic Mostly aquatic, although some live in soil or inside a host. A protist is any eukaryotic organism that is not a plant, animal or fungus.

Organization within Protista Kingdom Protista is divided into three dinctinct groups. While they are not phyla, these divisions are widely accepted. Animal-like protists Plant-like protists Fungus-like protists

Animal-like Protists These organisms are often referred to as protozoans. They live primarily in aquatic habitats, although some can be found in the soil and the digestive tracts of animals. Some protozoans are parasitic. All are unicellular except for one. All are heterotrophs that ingest their food and perform intracellular digestion.

Animal-like Protists They are divided into phyla based on their method of locomotion. Zooflagellates: use flagella for motion Sarcodines: use cytoplasmic extensions (pseudopods) for motion Ciliates: use cilia for motion Sporozoans: do not move

Zooflagellates Paramecium Vorticella

Sarcodines Amoeba Heliozoan

Ciliates Paramecium Tetrahymena

Sporozoans This photo shows the sporozoan known as a plasmodium. This species causes malaria and is transferred to a human host via mosquito bites.

Plant-like Protists Organisms in this group contain chloroplasts and are photoautotrophic. Includes all algae except for the blue –greens. May be unicellular, multicellular or colonial. The multicellular marine algae, the seaweeds, are similar to marine plants and may be moved to the plant kingdom. Almost all are aquatic or they live in very damp terrestrial environments.

The Phylums Rhodophyta – red algae Phaeophyta – brown algae Chlorophyta – green algae Pyrrophyta – dinoflagellates Chrysophyta – golden-brown algae and diatoms Euglenophyta – euglena

Algae Bloom- The Red Tide Brownie mix Cheese (yellow and orange) Chocolate milk Coffee creamer Cottage cheese Egg substitute Evaporated milk Frozen foods and desserts Frozen yogurt Ice cream Infant formula Margarine Mayonnaise Multiple vitamins Pet food Pudding (cooked) Relishes Salad dressing Sauces and gravies Sour cream Toothpaste Whipped topping Whipping cream Yogurt Algae, algae, everywhere…. in your ice cream, in your toothpaste?…

Fungi-like Protists Organisms in this group are unique in that they have both unicellular and multicellular stages. They are heterotrophic and perform extracellular digestion. They are decomposers and referred to as slime molds. The plasmodium is a well known slime mold.

Dog vomit slime mold