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Kingdom Protista. Kingdom Protista. Protozoa The Animal-Like Protists. Sec 26.1 Overview of Protozoa. Euglenoids. Plant like. Dinoflagellates. Plasmodial Slime Mold. Ciliophorans. Zooflagellates. Water Mold. Animal like. Cellular Slime Mold. Sarcodinians. Sporozoans.
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Kingdom Protista Protozoa The Animal-Like Protists
Euglenoids Plant like Dinoflagellates Plasmodial Slime Mold Ciliophorans Zooflagellates Water Mold Animal like Cellular Slime Mold Sarcodinians Sporozoans Protist Ancestor Brown Algae Green Algae Red Algae Golden Algae Diatoms
Euglenoids Plant like Dinoflagellates Plasmodial Slime Mold Ciliophorans Zooflagellates Water Mold Animal like Cellular Slime Mold Sarcodinians Sporozoans Diatoms Protist Ancestor Green Algae Brown Algae Red Algae Golden Algae
Characteristics of Protozoa • Single-celled microscopic eukaryotic organisms that are noted for their ability to move • Sometimes referred to as animal-like protists • Live in many environments • Most are heterotrophic, obtaining their nutrients by ingesting small molecules into food vacuoles
Characteristics - continued • Most live in aquatic environments • Many species make up zooplankton • Parasitic protists have complex life cycles that are very harmful to their host.
Reproduction • All protozoa can reproduce asexually, usually by binary fission • Some species reproduce by multiple fission • Some species are able to reproduce sexually through conjugation
Classification • Protozoa are classified based on the way they move • There are four phyla of protozoans
Adaptations • Many free-living species have a localized region of pigment, a substance that produces a characteristic color in an organism, called an eyespot or stigma. • Eyespots detect changes in the quantity and quality of light.
Adaptations - continued • Certain species also sense physical and chemical changes or obstacles in their environment • Most are separated from their environment by their cell membrane.
Adaptations - continued • Some species have the ability to survive in extreme conditions due to their ability to form cysts • A cyst is a dormant form characterized by a hardened external covering in which metabolic activity has ceased. • Many form cysts in response to changes in the environment such a drought, decrease in oxygen supplies, etc.
Phylum Sarcodina • Sarcodinesinclude hundreds of species of Amoebas, which inhabit freshwater, salt water and soil. • Sarcodines move by pseudopods, lobe extensions of cytoplasm, known as amoeboid movement.
Phylum Sarcodina - Movement • Pseudopodia forms when endoplasm pushes the ectoplasm forward to create an arm like extension • Then the cytoplasm streams into the pseudopodia and pulls the organism
Amoeba proteus Pseudopodium: part of the Amoeba used for locomotion.Ectoplasm: vitreous superficial layer of an Amoeba.Endoplasm: central part of an Amoeba.Cell membrane: membrane covering an Amoeba.Contractile vacuole: cavity of the amoeba that is able to contract.Food vacuole: cavity of the Amoeba responsible for digestion.Nucleus: central organelle for an Amoeba.Digestive vacuole: cavity of the Amoeba responsible for digestion.
Phylum Sarcodina - Feeding • Sarcodines also use pseudopodia for feeding. • When a sarcodine feeds, it surrounds the food with its pseudopodia. • A portion of the cell membrane then pinches together and surround the food to form a food vacuole, in a process called endocytosis. • Undigested food leaves the cell in a reverse process called exocytosis.
Phylum Sarcodina - Features • Most fresh water sarcodines have contractile vacuoles • When conditions are unfavorable ameobas survive by becoming cysts • Some sarcodinians have hard shell or tests of calcium carbonate or silica which has accumulated over the years to form Earth’s limestone beds.
Sarcodinians and Humans • Amoebas as cysts can spread by water, in food or on dirty dishes to spread Amoebic dysentry, which secretes enzymes that attack our intestinal lining • This disease can cause deep ulcers and other organ complications.
Phylum Ciliophora • Members of this phylum swim by means of cilia • The cilia is used for movement by beating like oars to propel the protist • Most ciliates live in freshwater.
Paramecium caudata • Pellicle – protective covering over the cell that regulates material in and out of the cell • Oral Groove, mouth pore, gullet and food vacuoles are where food travels to be digested • Anal pore – where undigested material is removed from the cell • Contractile vacuoles – remove excess water • Macronucleus – controls cell activities • Micronucleus– used in conjugation
Phylum Ciliophora - Conjugation • In conjugation, two opposite mating strains exchange genetic material • Although genetic material is exchanged during conjugation, no new cells are produced. • Following conjugation, each paramecium divides producing four genetically identical paramecia
Phylum Zoomastigina • The members of this phylum are characterized by the presence of one or more flagella • Some are free-living freshwater or marine organism
Phylum Zoomastigina • Many live inside other organisms in symbiotic relationships • The symbiotic relationships can be • Mutualistic – both organisms benefit • Parasitic – causes harm to the host
Phylum Sporozoa • Members of this phylum have adult forms with NO means of movement • Most sporozoans are spore-forming parasitic protozoans • The name sporozoan comes from the fact that when they are immature, they are surrounded by thick, sporelike walls
Phylum Sporozoa • Adult sporozoans have no structures for movement. • Immature sporozoans called sporozoites, can be transmitted through fluids from one host to another.
Kingdom Protista Algae The Plant-like Protists
Algae Characteristics • Algae are a diverse group of protists, they range in size from microscopic unicellular to large multicellular seaweeds. • Algae are autotrophic and perform plant-like photosynthesis because they have chlorophyll
Algae Characteristics continued • Algae are different from plants because the lack tissue differentiation and have no true roots, stems or leaves • The reproductive structures form gametes in single-celled gametangia, gamete chambers where as plants have a multicellular chamber.
Algae Characteristics continued • All algae • Areaquatic, live in freshwater or marine environments • Have flagella at some point in their life cycle • Have pyrenoids, which are special organelles that synthesize and store starch
Algae Structure • The body portion of an alga is called a thallus • The thallus comes in four different body types • Unicellular • Colonial • Filamentous • Multicellular
Unicellular Algae • Consists of a single cell • Most are aquatic organisms, form the phytoplankton • Produces half of the world’s carbohydrates and are among the major producers of oxygen
Colonial Algae • Have a structure that consists of groups of cells acting in a coordinated manner • Some cells become specialized for feeding and reproduction.
Filamentous Algae • Have a slender, rod-shaped thallus composed of rows of cells joined end to end. • Some have specialized holdfast cells that anchor them to the ocean bottom
Multicellular Algae • Have a large complex thallus • The leaf-like thallus may be several centimeters wide but only two cells thick • Some have rubber leaf-like portions, stem-like regions and enlarged air-bladders
Algae Classification • Chlorophyta • Phaeophyta • Rhodophyta • Bacillariophyta • Dinoflagellata • Chrysophyta • Euglenophyta • Algae are classified into seven phyla based on • color • type of chlorophyll • the way they store their food • the composition of the cell wall
Algae Reproduction • Many species of algae reproduce both asexually and sexually • Some species reproduce only asexually • Sexual reproduction is often triggered by environmental stress
Unicellular Reproduction Life Cycle of the unicellular green algae Chlamydomonas
Filamentous Reproduction Life Cycle of filamentous green algae Oedogonium
Phylum Chlorophyta – Green Algae • Contains more than 7,000 species of algae • Body structures range from single cells all the way to multicellular • Most species are aquatic • Green algae are green in color and live where there is lots of light for photosynthesis • Some live in symbiotic relationships with fungi called lichens
Phylum Phaeophyta – Brown Algae • Have a brown color due to the pigment fucoxanthin, are multicellular and most grow in cool saltwater habitats • Include giant kelps and seaweeds • They have specialized structures • Holdfast that anchors the thallus to the rocks • Stipe is the stem-like portion of the alga and leaf-like region that photosynthesizes is called the blade • Air bladders cause the blade, leaf-like portion, to float near the surface to capture sunlight
Phylum Rhodophyta – Red Algae • Are multicellular and grow in warm saltwater habitats • Have thalli with branched filaments • Have the pigments called phycobilins that give them the red color which allows them to trap light at deep levels of the ocean