KINGDOM PROTISTA

Protist Characteristics Organisms in the kingdom Protista first appeared about 1.5 billion years ago. Protists are eukaryotic organisms unlike Monerans.

Cell Types: Prokaryotes & Eukaryotes Monera All single-celled No membrane-bound organelles Genetic material not contained in membrane Protista, Fungi, Plantae, Animalia Single-celled or multicellular Membrane-bound organelles (ex. Mitochondria) Genetic material contained in a membrane - nucleus

General Characteristics Kingdom Protista contains 115,000 species extremely diverse in their cell structures, patterns of nutrition, metabolic needs, reproduction, and habitats. grab-bag of organisms that do not fit into the other kingdoms.

Classification difficult to classify so for the purposes of this class we will group them by their nutritional patterns. Animal-like protists (aka protozoans) Ingest – eat food Ex. Zoomastigina, Sarcodina (Amoeba), Ciliophora, Sporozoa Fungi-like protists Absorbtive Ex. Slime molds Plant-like protists Photosynthetic Ex. Chrysophyta, Euglenophyta, Pyrrophyta

Zoomastigina protists possess one or more flagella used for locomotion. Some zoomastigina are heterotrophic and feed on other protists. Other species live as internal parasites on animals, including humans and may be pathogenic. Ex. Sleeping sickness (a serious African disease) is caused Trypanosoma gambiensis. It’s carrier is the tsetse fly.

Giardia, a zooflagellate, can cause digestive problems in humans Giardia, a zooflagellate, can cause digestive problems in humans. This illness known as “beaver fever” is caused by drinking polluted lake water. Trichonympha, is a wood digesting zooflagellate which lives by the thousands in the guts of termites. Trypanosoma gambiensis Giardia Trichonympha

Amebae Single-celled protozoans with no set body shape. Create temporary projections of cytoplasm called pseudopods to move and feed. Feed on small organisms by endocytosis, engulfing organisms with their pseudopods.

Some amoebas are parasitic. Ex. amoebic dysentery is caused by a species of Entamoeba - enter the digestive system after a person drinks infected water. feed on the intestinal walls causing bleeding form cysts to prevent being digested and are passed out in the feces.

Ciliophora Ciliophora covered with hair-like projections (cilia) which move back and forth like oars to move the organism. Ex. paramecium

Sporozoa Sporozoans are protists that produce spores during their asexual phase of reproduction. They are non-motile and parasitic, obtaining their nutrients from the bodies of their hosts. Example : Plasmodium cause Malaria.

More Protists Fungus-like Protists All are heterotrophic and most are decomposers that feed on dead plants and animals tend to live in cool, damp places. Acellular slime moulds, cellular slime moulds Plant-like Protists 24,000 species of protists that contain chlorophyll and carry out photosynthesis.

Euglenophyta Euglenophyta are unicellular flagellates Euglena is a freshwater organism that moves using a flagellum. In the day, it is fully autotrophic and it photosynthesizes. In the dark, it become heterotrophic and feeds on dead organic material in the water.

Chrysophyta Diatoms- are a golden colouration due to yellow- brown pigments contained within their glasslike shells made of silica. Tremendously abundant in the oceans and are the key food source in marine and freshwater ecosystems.

Pyrrophyta extremely abundant in both marine and freshwater environments. Each species has a characteristic shape. They are luminescent when the surrounding water is agitated. produces a “red-tide” and also produces toxins. As shellfish and fish feed on them the toxins concentrate in their bodies and can move through the food chain.

Protista Review Questions 1 Protista Review Questions 1. What are some important differences between Monerans and Protists? 2. What three groups make up the kingdom Protista? 3. What characteristics distinguish plant-like protists from animal-like protists? 4. Would you expect all students to observe exactly the same shape when observing a live amoeba under the microscope? Explain. 5. What is a pseudopod? 6. Unlike the higher plants, plant-like protists do not have roots, stems, or leaves. Explain why they do not require these structures? 7. What is the function of the cilia on the surface of Paramecium? 8. All members of the Kingdom Protista (a) are eukaryotes (b) reproduce sexually (c) have cilia (d) don’t have a membrane around the nucleus 9. The Kingdom Protista is often described as the junk drawer when it comes to classification of organisms. Explain the meaning of this statement.