Kingdom Protista

Protists
Protists belong to the Kingdom Protista, which include mostly unicellular organisms that do not fit into the other kingdoms.
Characteristics of Protists

• mostly unicellular, some are multicellular (algae)
• can be heterotrophic or autotrophic
• most live in water (though some live in moist soil or even the human body)
• ALL are eukaryotic (have a nucleus)
• A protist is any organism that is not a plant, animal or fungus

Protista = the very first
Classification of Protists

• how they obtain nutrition
• how they move

Animallike Protists – also called protozoa (means “first animal”) – heterotrophs
Plantlike Protists – also called algae – autotrophs
Funguslike Protists – heterotrophs, decomposers, external digestion
Animal-like Protists: Protozoans
Four Phyla of Animal-like Protists -  Classified by how they move

• Zooflagellates – flagella
• Sarcodines – extensions of cytoplasm (pseudopodia)
• Ciliates – cilia
• Sporozoans – do not move

Zooflagellates
move using one or two flagella
absorb food across membrane
Ex.  Leishmania

Sarcodines
Ameba See Ameba Coloring Sheet
moves using pseudopodia ( “false feet” ), which are like extensions of the cytoplasm –ameboid movement
ingests food by surrounding and engulfing food (endocytosis), creating a food vacuole
reproducing by binary fission (mitosis)
contractile vacuole – removes excess water
can cause amebic dysentery in humans – diarrhea and stomach upset from drinking contaminated water
Other sarcodines: Foraminferans, Heliozoans

Ciliates
Paramecium (See Paramecium Coloring Sheet)
move using cilia
has two nuclei: macronucleus, micronucleus
food is gathered through the :mouth pore, moved into a gullet, forms a food vacuole
anal pore is used for removing waste
contractile vacuole removes excess water
exhibits avoidance behavior
reproduces asexually (binary fission) or sexually (conjugation)
outer membrane -pellicle- is rigid and paramecia are always the same shape, like a shoe