Kingdom Protista Protista Traditionally a kingdom level taxon Current evidence places organisms in as many as 3-5 kingdoms We will classify all: Unicellular or simple colonial Eukaryotic Organisms that are not fungi, plants or animals as members of the kingdom protista 1
Members of the Kingdom protista Are traditionally studied by breaking the kingdom into three informal groups: Algae capable of photosynthesis Slime and water molds heterotrophic saprophytes Protozoans heterotrophic animal like; parasites Protozoans: Giardia Giardia lamblia Causes giardiasis; aka beaver fever; drinking contaminated water Characteristics: Lack mitochondria Multiple flagella Two nuclei 2
Protozoans: Trichomonas Trichomonas vaginalis Considered an STD Characteristics: Multiple flagella Undulating membrane No mitochondria Protozoans: Flagellates Characteristics: Single large mitochondria Large flagellum Undulating membrane All are symbiotic; many are important parasites (symbiosis parasitic, mutualistic, commensal) 3
Examples : Trypanosoma brucei and T. gambiense cause African Sleeping sickness Life cycle includes a vector, an organism that transmits the infective stage of a parasite to a suitable host. The vector for African Sleeping sickness is Glossina, the Tse Tse fly T. cruzi causes Chaga s disease. Present in much of South, Central and parts of North America. Vector is an insect blood sucking cone-nosed bug 4
Protozoans: Malaria All are parasites Infective stage sporozoites These sporozoites have at their end (apex) a complex of organelles for penetrating host cells and tissues. Complex life cycle with sexual and asexual stages Example Plasmodium causes malaria Vector is a mosquito Currently affects over 300 million worldwide Know the life cycle!!! 5
Protozoans: Ciliates Solitary aquatic protozoans Cilia for locomotion Generally reproduce asexually by binary fission (cell division) Do have a sexual form of reproduction as well; simply for genetic diversity conjugation Pair of nuclei macronucleus and micronucleus Example : Paramecium During conjugation, micronuclei undergo meiosis and are swapped 6
Protozoans: Amoebas Uses pseudopodium (false foot) for: locomotion Feeding endocytosis called phagocytosis Amoeba proteus Examples 7
Chaos chaos Nagleria fowleri Causes Primary amoebic meningitis (PAM) 8
Entamoeba histolytica Causes amoebic dysentery Algae: Euglena Euglena autotrophic when sunlight is available Common in freshwater (aquatic) habitats 9
Algae: Diatoms Unicellular algae with a delicate glass-like test made of silica very strong Marine and freshwater forms (100,000 different species!) Uses of diatoms Producers in ecosystems Diatomaceous earth deposits for filters, pest control, nanotechnology 10
Algae: Brown algae Multicellular marine algae Resemble plants superficially; only as similar structures found in plants are analogous not homologous. Structure Body = thallus Consisting of stipe, blades, and holdfast Importance of brown algae Kelp forests in marine ecosystems Human consumption 11
Algae: Red algae Marine algae, smaller in general than phaeophytes Multicellular, red accessory pigments for photosynthesis Approx 6,000 spp. Red algae are also important producers in marine ecosystems and serve as food sources for humans as well (carrageenan) Algae: Green algae Named for green chloroplasts Closely related to plants (probably the ancestor of land plants was a green algae) Very diverse phylum some unicellular forms while others are multicellular or colonial 12
Common Spirogyra forms dense mats of filaments (chains of cell) and is able to reproduce sexually by conjugation. Slime and Water Molds Are fungal like in appearance Slime molds engulf nutrients much like amoebas Water molds form fungal like hyphae to decompose organic mater in water 13