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)

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

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

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

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)

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

Plant-like Protists: %%Unicellular Algae%%

Ecology:

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

Types:

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==

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

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

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)

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

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)

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

Classification:

• Common
• Sac
• Club
• Imperfect

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

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
  • 

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

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