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Eukaryotes

Eukaryotes. Protists. Endosymbiosis : 1st eukaryotes probably evolved process in which one prokaryote lives inside another. Gradually both host and guest become dependent on one another. cyanobacteria. that made energy for host. Protozoan or animal-like protists. Single-celled.

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Eukaryotes

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  1. Eukaryotes Protists

  2. Endosymbiosis:1st eukaryotes probably evolved process in which one prokaryote lives inside another. Gradually both host and guest become dependent on one another. cyanobacteria that made energy for host

  3. Protozoan or animal-like protists Single-celled. Microscopic. Eukaryotic. Divided by form of locomotion. Most heterotrophic.

  4. Move by pseudopods (false foot) and cytoplasmic streaming Engulfing other protists by phagocytosis Phylum Sarcodina

  5. Most fresh water Sarcodines havecontractile vacuole-organelle that removes excess H2O from cell. Unfavorable conditions, form hard cysts- can withstand drought, heat, or being eaten by others.

  6. Many have hard shells: Foraminiferans-shells of calcium carbonate. Radiolarians-shells of silica. When die, shells sink-deposits of limestone-chalk. Important food sources for many marine animals.

  7. Human disease Amoebic dysentery Carried as cysts in water, food, on dishes. In LI-secretes enzymes that attack intestinal lining, causing deep ulcers. Most reproduce asexually-produce 1 or more identical offspring.

  8. Phylum Ciliophora(Ciliaphorans, ciliates) Move with cilia-short hairlike cytoplasmic projections lining cell membrane. Most elaborate organelles of any protozoa.

  9. protective covering over membrane made of clear, elastic layer of protein. pumps excess water entering through osmosis (hypotonic environment). larger nucleus controls all functions, asexual reproduction by binary fission, and contains multiple copies of DNA. Food swept by cilia  oral groovegullet  food vacuolesanal pore. smaller nucleus for sexual reproduction by conjugation. Paramecium

  10. Sexual reproduction • Offspring genetically different from original paramecium. conjugation Binary fission • Gene exchange lets organisms adapt better to changing environments. Asexual reproduction

  11. Move by one or more flagella-long, hairlike structures made of microtubules Mutualistic- Trichonympha-in termites’ guts, help digest cellulose. Parasitic: Trypanosoma brucei-African Sleeping Sickness-tsetse fly: Toxins destroy RBCs, causes weakness. Untreated-attacks nervous system-death. Trypanosoma cruzi-Chagas' Disease: Transmitted by "Kissing Bug“. Fever and heart damage. Phylum Zoomastigina(zooflagellates)

  12. Phylum Sporozoa (sporozoans)-cause many human disease • Adults-no means of movement. • Immature sporozoites are surrounded by thick, sporelike wall and are transmitted thru fluids from 1 host to another. female Anopheles mosquito

  13. Homework: Read 22.1, pp. 533-541 Do Worksheet, pg. 83 http://www.glencoe.com/sec/science/biology/bio2000/pdfs/bdol19-1.pdf

  14. Algae, plantlike protistsAutotrophic Different from plants: • No tissue differentiation (no true roots, stems, leaves) • Different reproductive structures (single-celled gamete chambers)

  15. Alternation of generation • Reproduce: • Asexual-fragmentation-individual breaks up into pieces and each piece grows into new individual. • Sexual-triggered by environmental stress.

  16. Algae are classified into 7 Phyla, based on their color, type of chlorophyll, form of food storage substance, and cell wall composition • Things algae have in common: • All contain chlorophyll a. • Some also contain other chlorophylls (b, c, or d)that absorbs different wavelengths of light. • Some have accessory pigments (characteristic color). • Most aquatic. • Most have flagella at some point in their life cycle. • Often contain pyrenoids, organelles that make and store starch.

  17. Phylum Chlorophytagreen algae • Support they gave rise to land plants: • Both have Chlorophylls a/b, carotenoids. • Both store food as starch.  • Both also have cell walls made of polysaccharides, mainly cellulose.

  18. Phaeophyta-brown algae (seaweed)

  19. Rhodophyta(Red Algae-but not all red)

  20. Bacillariophyta-diatoms • Lack cilia and flagella. • Abundant part of phytoplankton-food web • Die-shells sink, form diatomaceousearth layer: • Made of two pieces that fit together like a box w/lid. • Slightly abrasive. • Major component of detergents, fertilizers, paint removers, insulators, some toothpaste.

  21. Dinoflagellatadinoflagellates • Free living have 2 flagella of unequal length-spin. • Symbiotic (no flagella) with jellyfish, mollusks, coral. • Like diatoms, produce organic matter. • Some produce nerve toxins and red pigments- • Population explodes-turn H2O brownish red-red tide. • Shellfish (oysters) feed on them, also consume toxins, dangerous to humans who eat them. • Some produce bioluminescence.

  22. Chrysophyta (Golden Algae) • 2 flagella of uneven lengths. • Form cysts when dry or very cold.

  23. 1-2 flagella. Show characteristics of both algae (may have chlorophyll) and protozoans (lack cell wall (have pellicle and are highly motile). Euglena-photosynthetic, but in dark, becomes heterotrophic. Euglenophyta-euglenoids

  24. Homework: Read 22.2, pp. 542-550 Do Worksheets, pp. 84-85 http://www.glencoe.com/sec/science/biology/bio2000/pdfs/bdol19-2.pdf

  25. Fungus-like protistsSlime molds Ecological role similar to that of fungi (decomposers). Differ from fungi in that slime molds ingest their food.

  26. 2 groups, both w/2 phase life cycle: • Most of their lives they spend in a mobile, amoeba-like feeding stage (eat organic matter and bacteria like protozoa). • Stationary reproductive stage-spore-bearing structure-fruitingbody (like fungus). • Cellular and plasmodial slime molds: • Shiny, wet appearance, a gelatin-like texture, and look more like a mold or fungus than anything else.

  27. Acellular (Plasmodial) Slime Molds • Diploid, multinucleate mass. • Creep along and phagocytize dead organic material and microorganisms. • Mass is one large cell (plasmodium)

  28. Unfavorable conditions (no food or moisture) • Spores resistant to extremes and germinate when environmental conditions become favorable.

  29. Cellular Slime Molds • Individual amoeboid cells eat bacteria/yeast. • When food becomes scarce, cells aggregate to produce a sluglike mass which produce fruiting bodies (reproductive structures). • Cells at tips become spore which germinate when conditions become favorable. • In sexual phase, two amoeboid cells fuse to form zygote and produce new amoeboid cells by meiosis.

  30. Consist of branching filaments of cells. Many are parasites of fish, insects, and plants. (Irish potato famine) Most species are saprobes (dead organic matter). Water Molds

  31. Homework: Read 22.3, pp. 551-554 pp. 555-557, #1-20, Assessing Knowledge & Skills, #1-4 Do Worksheet, pg. 86 http://www.glencoe.com/sec/science/biology/bio2000/pdfs/bdol19-3.pdf Do quiz and submit as before. http://www.glencoe.com/qe/science.php?qi=2509

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