Protists and Fungi

Protists

What is it?

• It is an organism that is not an animal, plant, fungus, or prokaryote
• Kingdom: Protista
• “The Very First” (the very first eukaryotes)

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Evolution

• First eukaryotic organisms on earth
• 1.5 billion years ago (bya)
• Endosymbitotic Theory: Eukaryotic cells may have evolved when multiple cells joined together into one.

Classification(s)

• Animal-like
• Plant-like
• Fungus-like

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Animal-like Protists (Unicellular):

Characteristics:

• All Heterotrophs
• 4 phyla: These are determined by movement
• Some are decomposers
• Base of some food chains
• Some cause disease

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Types:

Zooflagellates:

• They’re apart of the Phylum: Zoomastigina
• They swim using flagella   * Can either have 1 or 2
• Absorb food through their cell membrane
• Reproduce sexually (conjugation) or asexually

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Sarcodines:

• Phylum: Sarcodina
• Moving cytoplasmic extensions called psuedopods
• Amoeboid movement
• Capture food with psuedopods: food vacuole   * Food Vacuole: an organelle where food is stored after it’s captured     * Can cause disease (Pathogenic)       * Entomoeba       * Giardia causes disease that causes diarrhea

Ciliates:

• Phylum: Ciliophora
• Move through the use of cilia: hair-like projections that allows ciliates to move and get food
• Ciliate Anatomy (Paramecium)   * Trichocycts: structures used for defense   * Macronucleus: “working library” of genetic info (used for reproduction)   * Micronucleus: “reserve copy” of genetic info (used for reproduction)   * Gullet (Oral Groove): where food is trapped     * The food is collected here until it is stored in the food vacuoles   * Anal pore: where waste product is emptied

Contractile vacuole (sun shaped): collects/disperses water; maintains homeostasis

Ciliates Conjugation:

• Usually reproduce asexually: Mitosis
• Can exchange DNA through conjugation
• No NEW organisms are creates; simply an exchange of genetic info
• Occurs under stress (environmental pressures)

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Sporozoans:

• Phylum: Sporozoa
• Do not move on their own
• They are parasitic
• Have complex life cycles
• Malaria: caused by a type of protist called. . .   * Plasmodium

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Plant-like Protists: %%Unicellular Algae%%

Ecology:

• Phytoplankton: base of most aquatic food webs
• Algal blooms   * “red tides”

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Types:

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Euglenophytes:

• Phylum: Euglenophyta   * Phyta: “plant-like”
• Have two flagella
• ^^No cell wall; instead they have Pellicle^^
• Have eyespot: helps organism find sunlight to aide in photosynthesis
• 

Chrysophytes:

• Phylum: Chrysophyta
• Gold-colored
• Cell walls have carbohydrate Pectin rather than cellulose
• 

Diatoms:

• Phylum: Bacillarophyta
• Cell walls of Silicon (Si)
• 

Dinoflagellates:

• Phylum: Pyrrophyta
• Usually luminescent

Plant-like Protists: ==Multicellular Algae==

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Red Algae:

• Phylum: Rhodophyta   * “Red plants”
• Live at great depths
• Contain chlorophyll as well as Phycobillins (extra pigment) (absorb blue light, give off reddish color)

@@Brown Algae:@@

• Phylum: Pheophyta   * “Dusty plants”
• Have chlorophyll and fucoxanthin
• @@Largest and most complex algae@@
• Marine

Green Algae:

• Phylum: Chlorophyta   * “green plants”
• Share many characteristic with plants   * Cell wall of cellulose   * Chlorophyll a and b   * Hypothesized to be the ancestor of modern plants

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Human Use of Algae:

Medications:

• Treat ulcers, arthritis, and blood pressure

\ Food:

• Sushi wrap
• Algin (thickener) in candy bars, ice cream, pudding, salad dressing

\ Industry:

• Used to make plastics and waxes

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Fungi-like Protists:

• Heterotrophs
• Decomposes
• Lack cell wall
• Have centrioles
• Plant diseases: potato famine   * $Two Groups$     * $Slime Molds$       * Free-living cells in soil on the surface     * $Water Molds$       * Thrive on dead or decaying organic material in water, or plant       * (parasite)(on land)

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Fungi:

• Eukaryotic
• Heterotrophs   * Digest food on the outside of their body (external digestion), then absorb it   * All are multicellular, except yeasts
• Cell walls   * Made of chitin

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Structure:

• Hyphae: thin filaments that make up fungi   * Each hypha are only one cell thick   * Can form cross-walls
• Fungi bodies are composed of many hyphae tangled into a mass called:   * Mycelium: where food is absorbed (buried underground)
• Fruiting Body: reproductive structure above the soil (“mushroom” part)

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Reproduction:

• Asexually   * Hyphae break off and grow on their own   * Spores: a reproductive cell that scatters and grow new organisms
• Sexually   * Fusion of (+) and (-) nuclei that happens inside the fruiting body   * There are no males or females

Spreading:

• Spores are carried through wind or attached onto animals for them carry

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Classification:

• Common
• Sac
• Club
• Imperfect

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Common:

• Phylum: Zygomycetes
• Life cycle includes a Zygosporangium: resting spore that contains zygotes (until conditions become favorable to spread)
• Bread Mold:   * Structure and Function of Bread Mold:     * Rhizopus Stolonifer     * Rhizoids (mycelium): rootlike hyphae that penetrate the bread’s surface
• Stolons: stem like hyphae that run along surface
• Sporangiophores: hyphae that push into air   * Contain 40,000 spores; each able to grow new fungus

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Sac Fungi:

• Phylum: Ascomycota
• Ascus: reproductive structure that contains spores
• Largest phylum of fungi
• Yeasts:   * Unicellular fungi   * Used for baking and brewing   * Dry granules are ascospores   * Budding: asexual reproduction

Club Fungi:

• Phylum: Basidiomycota
• Specialized reproductive structure that resembles a club   * Basidium (spores): the whole cap itself
• Life Cycle:   * Mushroom cap; has gills; lines with basidia   * 2 haploid nuclei fuse creating diploid zygote   * Undergoes meiosis, producing haploid basidiospores   * Basidiospores are then scattered
• Edible and Inedible   * Many wild mushrooms are poisonous   * Can look identical to edible types   * Don't eat the shrooms   *

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Imperfect Fungi:

• Phylum: Deuteromycota
• Varied
• Placed in this phylum because a sexual phase has never been documented by researchers
• Majority of them resemble ascomycetes
• Penecillium

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Fungi Ecology: Decomposers

• All Heterotrophs
• Most are saprobes: obtain food from dead or decaying organic matter
• Maintain equilibrium in every ecosystem
• Parasites:   * Plant     * Wheat rust     * Corn smut   * Human     * Ringworm     * Athlete’s Foot   * Animal     * Cordyceps in grasshoppers in Costa Rica

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