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

Paramecium (Kingdom: Protista/ Phylum: Ciliaphora)

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