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PROTISTA. Characteristics of Protists. Eukaryotic Mostly unicellular Autotrophic and heterotrophic forms. PROTOZOA. Amoeboid Protozoa. Protozoa with false feet, or pseudopodia Movement by amoeboid movement which is accomplished by cytoplasmic streaming Ingest food by phagocytosis
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Characteristics of Protists • Eukaryotic • Mostly unicellular • Autotrophic and heterotrophic forms
Amoeboid Protozoa • Protozoa with false feet, or pseudopodia • Movement by amoeboid movement which is accomplished by cytoplasmic streaming • Ingest food by phagocytosis • Reproduction by binary fission
Flagellated Protozoa—have at least one flagellum for movement. Parasitic forms cause diseases. • Trypanosoma—causes African sleeping sickness. Transmitted by the tsetse fly. • Giardia—carried by muskrats and beavers. Characterized by fatigue, diarrhea, cramps, and weight loss. May be fatal. • Leishmania—carried by sand flies, causes leishmaniasis which is characterized by disfiguring skin sores and may be fatal.
Sporozoa • Spore-bearing protozoa • All are parasitic and non-motile • Sporozoan responsible for malaria is transmitted by mosquitoes
Ciliated Protozoa • Protozoa that move using cilia • Most commonly studied example of this genus is called Paramecium • Ingest food through oral groove covered by cilia • Reproduction is by binary fission or conjugation
The protozoa contribute to the make up marine zooplankton which are an important part of the ocean’s food chain.
Green Algae—includes unicellular, colonial, filamentous, and thalloidforms • Spirogyra—spiral chloroplasts, filamentous • Chlamydomonas—cup-shaped chloroplast, unicellular • Volvox—spherical colonies • Ulva—thalloid
Euglenoids • Euglena is the best known genus in this group • Forms of algae that possess flagella and also contain chloroplasts • Have a red eye-spot used to detect and move toward light • Nutrition by photosynthesis unless placed in the dark, then they become heterotrophic
Flame-colored Algae (dinoflagellates) • Contain a flame colored pigment in addition to chlorophyll • Each is a one-celled organism which bears two flagella • Cause the red tide which occasionally appears in the Gulf of Mexico • Certain types of these algae may also exhibit bioluminescence
Golden-brown Algae (diatoms) • Contain a yellow green pigment in addition to chlorophyll • Diatoms are distinguished by their “glass” walls, formed primarily of silica
Brown Algae • All are multicellular and usually large • Thallus consists of a holdfast (anchors to a rock), a stipe (stem-like structure), bladders (for buoyancy), and blades or fronds (leaf-like structure where photosynthesis occurs) • Cell walls contain alginic acid, a source of commercially important alginates
Red Algae • Mostly marine and multicellular • Usually less that I m long • Commonly grow at depths of 150 m and have been discovered at depths of 268 m • Cell walls coated with a sticky substance called carageenan (polysaccharide)
The unicellular algae make up marine phytoplankton which are also an important part of the ocean’s food chain.
Fungus-like Protists—lack chloroplasts and absorb nutrients from dead organic matter. Lack the chitin in the cell walls of true fungi. Slime Molds Water Molds and Downy Mildews
Economic Importance of Kingdom Protista • Important part of aquatic food chains • Diatomaceous earth has numbers of uses • It is generally believed that an unknown but significant percentage of the world’s oil supply is of diatom origin • Fish kills due to red tides • Fouled drinking water • Ruined recreational sites due to dense algal growths • Certain types of seaweed may be used for food • Alginates and carageenan from seaweed may be used for cosmetics, in the production of drugs and vitamins, and in the production of some foods
Diseases Caused by Protozoa • Amoebic dysentery and amoebic meningitis caused by a type of amoeba. • African sleeping sickness caused by Trypanosoma gambiense, is spread by the tsetse fly. • Leishmaniasis caused by Leishmania donovani, causes enlargement of the liver and the spleen as well as numerous sores on the skin. Occurs in India, northern Africa, and parts off South America. • Giardiasis is an infection of the small intestine caused by a microscopic organism, Giardia lamblia. It can be contracted by drinking water from lakes or streams where water-dwelling animals such as beavers and muskrats have caused contamination. • Malaria, caused by a species of Plasmodium, is spread by mosquitoes. Ranks as one of the most serious infectious diseases on the globe.
Characteristics: • Eukaryotic • Unicellular and multicellular forms • Absorptive nutrition (heterotrophic) • Mycelium—body of the fungus • Hyphae—threadlike structures that make up the body of the fungus • Reproduction—both sexual and asexual • Cell walls contain chitin
Zygote Fungi • Mycelium (body) composed of hyphae that run through and on the substance upon which they are growing • Mycelium bears sporangia, which produce spores for the reproductive process • An example of this type of fungus is bread mold (Rhizopus) • Sexual reproduction by production of zygospores
Sac Fungi • Characterized by the formation of saclike structures called asci, which usually contain four to eight spores • Fungi in this class cause many important plant diseases including chestnut blight, Dutch elm disease, and powdery mildew
Types of sac fungi: Cup fungi Morels
Types of sac fungi: Truffles Penicillium
Types of sac fungi: Ergot Yeast
Club Fungi • Characterized by basidiospores borne on small clubs, or basidia • Mushrooms and toadstools are the most common type of club fungus
Types of club fungi: Gill fungi Shelf or bracket fungi
Types of club fungi: Puffballs Stinkhorn fungus
Types of club fungi: Rusts Smuts