Chs' 1920: Protists and Fungi

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Chs. 19-20 Protists and Fungi

• The First Eukaryotes

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19-1 Protist Characteristics

• Eukaryotic (have nucleus, organelles)
• Unicellular or multicellular in colonies
• Sizes range from microscopic to 1 meter long
• Autotrophic (make own food) or heterotrophic
  (decomposers/absorb food, predators, parasites)
• Reproduction sexual by meiosis or asexual by
  fission, some both
• Habitats Damp or aquatic environments
• Oldest fossils are 1.5 Billion years old

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• 19-2 Animal-Like Protists
• Also called Protozoans
• Heterotrophic (consume food) predators
• Motile (move)
• Phylum Ciliophora have hair-like cilia to move,
  special organelle contractile vacuole (collects
  water), ex. Paramecium p. 548
• Phylum Sarcodina move with pseudopods false
  feet, special organelle food vacuole digest
  food, cause Amebic Dysnnterey (dehydration and
  diahrrea) ex. Amoeba p. 550
• Phylum Apicomplexa sporozoans cause diseases
  like malaria when carried from mosquito to red
  blood cells ex. Plasmodium p. 551
• Phylum Zoomastigina zooflagellates, parasites
  that cause disease like African Sleeping Sickness
  p. 552

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• 19-3 Plant-like Protists
• Have cell walls
• Producers
• Can live in colonies (kelp)
• Use life cycle called alternation of generations
  (2 generations, one reproduces sexually, one
  asexually)
• Produce 30-40 of world oxygen
• Phylum Chlorophyta 7000 species of green
  algae, used for food and as a food/paint
  thickener, ex. Volvox
• Phylum Euglenophyta freshwater, swim with 2
  flagellla, ex. Euglena
• Phylum Phaeophyta brown algae, ex. sea kelp
• Other phyla include red algae, golden algae,
  dinoflagellates (cause red tides), diatoms

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• 19-4 Fungus-like Protists
• Decomposers that absorb food into cells from
  decaying materials
• Cell walls made of chitin
• Release spores to reproduce
• 2 Phyla of slime molds Acrasiomycota and
  Myxomycota, live on rotting logs and leaves,
  slug-like movement in feeding stage, ex. Physarum
  p. 562
• Phylum Oomycota water molds, p. 564

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Algae green, red
Euglena
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paramecium
amoeba
cilia
pseudopod
diatom
Slime mold
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20-1 Fungi Characteristics

• Eukaryotic
• Heterotrophic decompose and absorb organic
  materials from living or dead organisms
  (saprophytes)
• Have cell walls (like a plant) made with strong
  carbohydrate Chitin
• Store energy in form called glycogen (like
  animals)
• Many live in symbiosis with another organism,
  where both benefit each other mutually. Ex a
  lichen is a symbiosis between a fungus (provides
  water, minerals) and algae (provides food)
• Are divided into 4 phyla according to life cycles.

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3 Fungus Structures

• 1) hyphae thread-like filaments that grow down
  into food source, also used for reproduction.
  Most of the body of a fungus is this, out of
  sight.
• 2) mycelium cottony mass of threads that grow
  through the food source, releasing enzymes to
  break down and absorb food.
• 3) fruiting body a reproductive structure that
  holds spores.

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Fungal Reproduction

• Asexual without recombining genes
• Simple spore formation
• Fragmentation of hyphae to produce a new fungus
• Sexual opposite hyphae fuse together and then
  split to make spores. New gene combinations are
  produced this way.

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Fungal Phyla and Examples

• Phylum Basidiomycetes Club fungi, ex.
  Mushroom
• Phylum Zygomycetes small, fuzzy appearance, ex.
  Rhizopus (Bread mold)
• Phylum Ascomycetes Sac fungi, exs. yeasts
  (only single-celled fungi), Ringworm
• Phylum Deuteromycetes Imperfect fungi none
  have been witnessed using sexual reproduction,
  ex. Penicillium

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Fungal Relationships

• Parasitism
• 1) Wheat rusts and corn smuts destroy crops
• 2) Ringworm forms ring on skin, spores spread
  by contact
• 3) Athletes Foot - forms on skin, feeds on
  keratin
• 4) Nail fungus feeds on nail protein
• Mutualism
• 1) Lichen symbiosis between algae and a dense
  web of fungus (food, water/minerals)
• 2) Mycorrhizae fungal hyphae live with roots
  of plants to absorb water and minerals for plant,
  receive food from plant photosynthesis (orchid)

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