1 Ch Protists

2 20–1 The Kingdom Protista  What Is a Protist? diverse group diverse group may include more than 200,000 species may include more than 200,000 species eukaryotes eukaryotes most protists are unicellular most protists are unicellular Protista, comes from Greek words meaning “the very first Protista, comes from Greek words meaning “the very first appeared nearly 1.5 billion years ago appeared nearly 1.5 billion years ago

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4 Classification of Protists  classify protists according to the way they obtain nutrition  heterotrophs are called animal-like protists  produce their own food by photosynthesis are called plant-like protists  obtain their food by external digestion— either as decomposers or parasites—are called fungus-like protists

5 20–2 Animal-like Protists: Protozoans

6  Animal-like protists were called protozoa, which means “first animals”  heterotrophs  four phyla of animal-like protists (distinguished by their means of movement) zooflagellates - flagella zooflagellates - flagella sarcodines - move by extensions of their cytoplasm (pseudopodia) sarcodines - move by extensions of their cytoplasm (pseudopodia) ciliates - cilia ciliates - cilia sporozoans - do not move sporozoans - do not move

7 Zooflagellates  phylum Zoomastigina  Flagella (one or two, a few have more)  absorb nutrients through cell membrane or live inside other organisms  Most reproduce asexually  Some have a sexual life cycle (form gametes)  Ex: Trypanosoma, Leishmania, Giardia, Trichonympha

8 trypanosomaLeishmaniaGiardiaTrichonympha

9 Sarcodines  phylum Sarcodina  heterotrophic; some parasitic  Move by pseudopods  form food vacuoles  Foraminiferans are abundant in the warmer regions of the oceans (shells of calcium carbonate (CaCO 3 )  Heliozoans - heliozoa means “sun animal” spikes of cytoplasm, supported by microtubules, project from their silica (SiO 2 ) shells spikes of cytoplasm, supported by microtubules, project from their silica (SiO 2 ) shells

10 Foraminiferans Amoeba Radiolaria Heliozoans

11 Ciliates  phylum Ciliophora  Heterotrophic  use cilia for feeding and movement  Most ciliates are free living Fresh or salt water Fresh or salt water  Trichocyst = small, bottle-shaped structure used for defense by paramecia

12  Cilia  Trichocyst = small, bottle-shaped structure used for defense by paramecia  Macronucleus (working genes) and one or more smaller micronuclei (backup copy)  Gullet = indentation in one side of a ciliate that allows food to enter the cell  anal pore = region of the cell membrane of a ciliate where waste-containing food vacuoles fuse and are then emptied into the environment  contractile vacuole = cavity in the cytoplasm of some protists that collects water and discharges it from the cell Internal Anatomy

13Paramecium

14 Conjugation  exchange genetic material  increase in genetic diversity  sexual process

15 Sporozoans  phylum Sporozoans  Do not move on their own  Parasites  complex life cycles that involve more than one host

16 Animal-like Protists and Disease  Ex: malaria and African sleeping sickness Malaria:  2 million people still die from malaria every year.  Caused by: Plasmodium (sporozoan)  Carried by: Anopheles mosquito  infects liver cells and then red blood cells  severe chills and fever  Drugs and vaccines are only partially effective

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18 African sleeping sickness:  Caused by: Zooflagellates of the genus Trypanosoma  Carried by: tsetse fly  chills and rashes, can infect nerve cells

19 Amebic dysentery:  severe diarrhea  Caused by: Entamoeba  Found in contaminated drinking water  Common in areas with poor sanitation  also found in ponds and streams

20 20–3 Plantlike Protists: Unicellular Algae  Photosynthetic, often motile  Often called algae  Base of the ocean food chain  Use chlorophyll and accessory pigments  4 phyla of unicellular algae: Euglenophytes Euglenophytes Chrysophytes Chrysophytes Diatoms Diatoms Dinoflagellates Dinoflagellates

21  Group of small photosynthetic organisms that float near the surface of the water. Oceanic phytoplankton is the primary food source, directly or indirectly, of nearly all sea organisms. Composed of groups such as diatoms, dinoflagellates, and coccolithophores, phytoplankton varies seasonally in amount, increasing in spring and fall with favourable light, temperature, and minerals. (From: US Britannica Online) 20–3 Plantlike Protists: Unicellular Algae

22 Euglenophytes  2 flagella  No cell wall  Eyespot = helps the organisms sense light  Pellicle = tough and flexible cell membrane, folded like a ribbon

23 Chrysophytes  yellow-green algae and the golden-brown algae  cell walls of some chrysophytes contain the carbohydrate pectin instead of cellulose  store food in the form of oil rather than starch

24 Phytoplankton -Diatoms  Among the most abundant and beautiful organisms on Earth  produce thin, delicate cell walls rich in silicon (Si)—the main component of glass  shaped like the two sides of a petri dish or flat pillbox, with one side fitted snugly into the other

25 Phytoplankton -Dinoflagellates  half are photosynthetic; half live as heterotrophs  two flagella  Many species are luminescent

26 Algal Blooms Algal Blooms  absorb organic material  vital role in recycling sewage and other waste materials  Can grow very fast when nutrients are abundant  “red tide”  Produce a deadly toxin  makes shellfish dangerous to eat

27 20–4 Plantlike Protists: Red, Brown, and Green Algae  multicellular  Often called seaweed  most important differences among these phyla involve their photosynthetic pigments  3 phyla of planktonic algae: Red algae Red algae Brown algae Brown algae Green algae Green algae

28 Red Algae  live at great depths due to their efficiency in harvesting light energy  Color: green, purple, red, black

29 Brown Algae  largest and most complex of the algae  cool, shallow coastal waters  giant kelp; sargasso sea

30 Green Algae  Cellulose cell walls  Share common ancestors of modern land plants Chlamydomonas

31 Human Uses of Algae  Thickeners for food  Drugs for stomach ulcers  Chemicals in paints, plastics, and waxes  Produce oxygen

32 20–5 Fungus-like Protists  Heterotrophs  damp, nutrient-rich environments and absorb food through their cell membranes  Recycle organic wastes  No chitin  Three groups: cellular slime molds cellular slime molds acellular slime molds acellular slime molds water molds water molds

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34 Slime mold movies  avi avi avi   

35 Ch Fungi

36 21–1 The Kingdom Fungi 21–1 The Kingdom Fungi What Are Fungi?  over 100,000 species  eukaryotic heterotrophs  cell walls made of chitin  digest food outside of their bodies and then absorb it  Some live as parasites  reproduce both asexually and sexually  Spread by forming spores

37 Structure of Fungi

38 Types of Fungi Yeast Club Fungi Black Bread Mold Sac Fungi

39Facts  Some are edible, some poisonous  Penicillium notatum grows on plants and is used as an antibiotic  Oldest fossil = 460 million years ago  Feed on living and dead organisms  Many fungi are saprobes - organisms that obtain food from decaying organic matter  Some fungi are carnivorous  Some cause plant and animal diseases

40 Penicillin fungi Poisonous Fungi Carnivorous Fungi

41 Fungal Diseases

42 Fungi as Decomposers  essential role in maintaining equilibrium in nearly every ecosystem  recycle nutrients by breaking down the bodies and wastes of other organisms