Transcript Slide 1
Kingdom Protista What’s a Protist? • Protist, not Protest • Protists are: – Eukaryotes (cells have nucleus & organelles) – Mainly single-celled, but have multicellular also – Not a fungus, a plant, or an animal • 3 Types: – Animal-Like, Plant-Like, & Fungus-Like Protists Animal-Like Protists • Known as PROTOZOANS (first animal) • Heterotrophic – Get energy from other organisms • 4 Types: distinguished by their movement – Zooflagellates – Sarcodines – Ciliates – Sporozoans Zooflagellates • Move by using FLAGELLA • Have one or two flagella • Absorb food through cell membrane from dead organisms • Live in streams or lakes • Reproduce Asexually by mitosis or Sexually by meiosis Sarcodines • Move with PSEUDOPODS – These are cytoplasmic extensions • Also use PSEUDOPODS for feeding – They surround food with membrane making a food vacoule • Examples: – Amoebas, Foraminiferans, & Heliozoans Ciliates • Use CILIA for feeding and movement – Instead of having only 1 or 2, they have many cilias • Use cilia to move food into gullet and make food vacoule • Reproduce their mitosis • Also go through conjugation to pass genes (just like some bacteria) • Example: Paramecium Sporozoans • Unique because they don’t move freely • PARASITIC – live in host • Reproduce through SPOROZOITES – Sporozoites attach to a host cell and penetrate it to live in it Protozoans & Diseases • Malaria – Caused by sporozoan Plasmodium – Passed on by mosquitoes • African Sleeping Sickness – Caused by zooflagellate Trypanosoma – Transmitted by bite of the tsetse fly – Effects nervous system; fall into fatal sleep • Amebic Dysentary – Caused by amoeba Entamoeba Part 2 Plant-Like Protists – Unicellular • Unicellular ALGAE • Why plant-like? – Because contain pigments & photosynthetic – Contain chlorophyll & accessory pigments • 4 Types: 1) Euglenophytes 2) Chrysophytes 3) Diatoms 4) Dinoflagellates Euglenophytes • Have 2 flagella • Have chloroplast & chlorophyll – Unlike plants = no cell wall – For protection instead have Pellicle • Have EYESPOT = cluster of red pigments to help find sunlight • Reproduce asexually by Binary Fission Chrysophytes • Name means “Golden Plants” • Yellow-Green Algae • Cell wall contains pectin & cellulose • Store food as oil, not starch (like plants) • Reproduce asexually & sexually Diatoms • Most abundant organism • Cell walls made of silicon (Si) – Silicon is the main component of glass • Look like two petridishes on each other • When they die, make Diatomaceous Earth Dinoflagellates • • • • ½ are Photosynthetic & ½ are Heterotrophic Have 2 flagella that wrap around body Cell wall made of Cellulose (like plants) Reproduce asexually (Binary Fission) Plant-Like Protists – Multicellular • Multicellular ALGAE 1) Green Algae 2) Red Algae 3) Brown Algae • Biggest Difference is their Pigments Green Algae • Extremely similar to plants: – Have chlorophyll a and b – Cell walls of cellulose – Stores food as starch • Can be unicellular, colonial, & multicellular Brown Algae • Contains chlorophyll a and c • Also contains fucoxanthin (brown pigment) • Largest known algae, Giant Kelp General Structure: Red Algae • Have chlorophyll a & phycobilins (red pigment) • Good at making energy, so grow in deep water • Important to coral reefs Reproduction in Algae • Many life cycles have two generations: – Haploid (n) = Spores & Gametes – Diploid (2n) = Sporophyte & Zygote Human Uses of Algae • Major Food Source 1) Sushi • Dried & used as a wrap (Porphira – red algae) • Also used for salad (Green algae) 2) Ice cream, Cheese, Syrups, Puddings • Algin – Brown Algae • Carrageenan – Red Algae • Industrial Uses – Algin used for paint, rubber, cosmetics – Pigments also used for medicine & pharmaceuticals Part 3 Fungus-Like Protists • Like fungus, these are Heterotrophs – Absorb nutrients from dead organisms • Key role = recycle organic material • Unlike true fungus: – Have centrioles – Don’t have chitin cell walls • 2 Types: 1) Slime Molds & 2) Water Molds Slime Molds • Two Groups: – Cellular Slime Molds & Acellular Slime Molds (seperated by cell membrane) (cells fuse to form 1 with many nuclei) • Cellular Slime Molds – Free Living, but release chemicals to attract individuals – Form colonies – Reproduce by Fruiting Body that releases spores • Acellular Slime Molds – Single cells fuse together to form PLASMODIA – Fruiting bodies spring up and release spores with flagella Water Molds • Thrive on dead or decaying organisms • Some live on land as plant parasites • Produce HYPHAE: – Many cells together – Cell walls made of cellulose – Produce spores that are motile • Reproduce both asexually & sexually – Antheridium = produces male nuclei – Oogonium = produces female nuclei