Characteristics and Reproduction of Protists: A Study of Protozoa

1. Protozoa Chapter 26

2. Characteristics of Protists • Have nucleus i.e. eukaryote • Lack tissue differentiation • Unicellular • Move independently • Ocean, fresh water, crawl in soil (some water) • Heterotrophic • Food vacuoles break down particles • Both free-living and parasitic • Zooplankton - Primary source of energy for organisms in ecosystem

3. Reproduction • Asexually • binary fission – produce one identical organisms • multiple fission – produce several identical organisms • Sexually – conjugation

4. Binary fission

5. Multiple fission

6. Conjugation • Paramecia pair up • Macronuclei disntegrate & micronuclei undergo meiosis • All but one micronuclei disintegrates. It undergoes mitosis. • Each paramecium exchange 1 micronuclei • Micronuclei fuse • Paramecia separate and marconucleus re-form

7. Adaptations • Eyespot – localized region of pigment that detects light variations in the environment • Cyst – a hardened external covering that stops all metabolic activity when organism is outside of host to survive in harsh environments • e.g. nutrient deficient, drought, decrease oxygen, or pH/temp changes

8. 4 phyla – named for type of movement (locomotion) 1. Ciliophora • Ciliates 2. Sporazoa • sporozoans Plasmodium Zoothamnium

9. phyla cont’ 4. Sarcodina • sarcodines 3. Zoomastigina • Zooglagellates Amoeba proteus Trichomonas vaginalis

10. Phylum Sarcodina • Movement:Pseudopodia – “false feet” - cytoplasmic extensions • Ex: Amoebas inhabit fresh/salt water, and soil • Endoplasm – inner portion of the cytoplasm • Ectoplasm – outer layer • Ameboid movement powered by Cytoplasmic streaming – internal flowing of a cell’s cytoplasm

11. Eating (heterotophic) • Phagocytosis – engulf other protists • Endocytosis – when membrane surrounds and pinches together into food vacuole • Exocytosis – when undigested food exits the cell • Contractile vacuole – organelle that expels fluid from cell b/c hypertonic to environment • *remember – water moves from high concentration to lower – hypertonic is high solute concentration relative to environment

12. Amoeba

13. Amoeba

14. Movement & eating • BEST one - http://www.mikrofauna-videos.de/videos.php?lang=en&id=amoeba&PHPSESSID=d48af6fdb76a70938e775b3af8bb2d7b • http://www.kent.k12.wa.us/staff/timlynch/sci_class/chap09/lesson_protista/Amoeba%20Move.html • http://www.microscopy-uk.net/coppermine/displayimage.php?album=82&pos=0

15. Variations • Foraminifera – ancient, live in oceans with shelled protective covering – tests • Radiolarians – ancient, live in shallow waters • Tests sink to bottom and build up layers of sediment • E.g. White Cliffs of Dover, England

16. White Cliffs of Dover, England

17. 300 foot cliffs made from tests of foraminifera and radiolarians

18. FYI • Sediment can accumulate as slowly as 0.1 millimeter (0.04 inch) per 1,000 years (in the middle of the ocean where only wind-blown material is deposited) to as fast as 1 meter (3.25 feet) per year along continental margins. More typical deep-sea rates are on the order of several centimeters per 1,000 years.

19. Foraminifera/Radiolarians

20. Human disease • Amebic dysentery – sometimes fatal • Enters from contaminated food and water • Enzymes break down intestinal wall

21. Phylum Ciliophora • Movement – cilia • ex: paramecium lives in fresh/salt water ponds & slow moving streams • Eat: bacteria & algae • Reproduce: Asexual – binary fission followed by sexual – conjugation – offspring genetically different (page 515)

22. Paramecia

24. Contractile vacuole operation

25. Food vacuole

26. Phylum Zoomastigina • Movement: flagella in lakes & ponds • Ex: Giardia lamblia • Eat small organisms • Live in blood of fish, amphibians reptiles, birds, & mammals carried by bloodsucking insects from host to host

27. Disease • Trypanosomiasis – parasitic • African “sleeping sickness” • Transmitted by tsetse fly • Chagas’ disease - parasitic • Transmitted by “kissing bug” • Leishmaniasis – parasitic • Can be fatal • Transmitted by sand flies • Giardiasis – parasitic • Transmitted by animal feces in contaminated water

28. Phylum Sporazoa • Movement: only as juvenile • Ex: Plasmodium

29. Disease • Malaria – • Transmitted by mosquito • Causes fever, fatigue, thirst, anemia, and death • Occurs in cycle • Problem treating b/c mosquitoes developed resistance to quinine • Afflicts 500,000,000 people per year • Kills 2,700,000 million per year • page 518 life cycle

30. analogies • _______: _________:: _______: ______ disease cause • _______: _________:: _______: ______ • _______: _________:: _______: ______

32. Algae Chapter 27

33. Characteristics • Eukaryote • Autotrophic (differ from other protozoans) • Have chloroplasts • Unicellular and/or multicellular • Lack tissue differentiation

34. 4 types of algae based on body structure (thallus) • Unicellular – aquatic – ex: phytoplankton • Base of food chain • Produce oxygen • Colonial - ex. Volvox • Many cells grouped & working together

35. 4 types of algae cont’ 3. Filamentous – ex. Spirogyra • Some anchor to ocean floor 4. Multicellular – ex. Macrocystis - giant kelp • These are most like plants (see pictures next slide)

36. Giant Kelp - Macrocystis

37. Classification • 7 phyla based on: • Color • Chlorophyll type • Pigments absorb differing wavelengths of light so gives them their characteristic color- green brown red • Food-storage • Cell wall composition

38. Reproduction with unicellular algae • Asexually – mitosis produces haploids • + and – gametes called zoospores • Sexually – when + and – join to form diploid zygote – zygospore – meiosis (page 528)

40. Reproduction in multicellular algae • Complex • Page 528

41. Ulva – sea lettuce • Gametophyte – haploid gamete-producing phase • Sporophyte – diploid spore-producing phase • Page 529

42. Phylum Bacillariophyta • Diatoms – cell wall called shells, have 2 pieces (like box with lid) • Diatomaceous earth – dead diatoms sink & form sediment • used in commercial products like: detergents, paint removers, fertilizers, insulators, & toothpaste

43. Phylum Dinoflagellata • Unicellular, photosynthetic • Red tide – population explosion

44. Phylum Euglenophyta Euglena – unicellular with flagella • Plantlike b/c photosynthetic • Animal-like b/c lack cell wall

45. Protozoa Images • www.microimaging.ca/protozoa/conjugation.html

46. Protista Quiz • http://www.okc.cc.ok.us/biologylabs/Documents/Zoo/Protista.htm

47. Slime molds • Eukaryote • Multicellular • heterotrophic • Fungus-like • Usually red, viscous mass • Live in damp soil, rotting logs, decaying leaves • Ameboid movement “ooze” • Eat by phagocytosis

48. Water molds • Fungus-like with branching filaments • Aquatic, soil and parasitic • Blight – disease causes decay of plant • Irish potato famine

49. Review • Animal-like protists • amoeba & paramecium • Plant-like protists • Spirogyra & volvox

50. Review analogies • _______: _________:: _______: ______ disease cause • _______: _________:: _______: ______ • _______: _________:: _______: ______