Kingdom Fungi Ch 20

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Kingdom FungiCh 20
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General Characteristics of Fungi

• Ubiquitous
• Decompose
• Some are parasitic, some are mutualistic
• Have plant animal characteristics

• PLANT many are anchored in the ground cell
  walls (but NOT of cellulose)
• ANIMAL Heterotrophic
• On the dead and on living
• What do we call these 2 groups?

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Fungi General Characteristics

• Mostly multicellular
• A few are unicellular
• Most of life cycle is haploid
• They have a nucleus
• Many have multiple nuclei
• They have a cell wall
• Made of chitin
• Digestion is EXTRACELLULAR!
• They secrete an enzyme that breaks down nutrients
  THEN they take them in
• NO PHOTOSYNTHESIS!

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FUNGI STRUCTURE

• Made of thin filaments hyphae (fuzzy)
• Hyphae can grow as individual cells or may fuse
  together
• there are different types of hyphae
• some for reproduction, some for growth, some for
  stability (sturdy)
• Hyphae that form a web and work together
  Mycelium

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6. Structure Hyphae Types/Functions

• a) Rhizoid
• Anchor the fungus in its food source
• b) Stolon
• Run along the surface of the food source
• Give rise to 2 mating forms ( and -)
• Sexual reproduction growth
• c) Sporangia
• Also called fruiting bodies
• Swell at the tips of sporangiophores
• Contain the spores used for
• asexual reproduction

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What are the dots around the sporangium?
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Hyphae

• All Fungi except for yeast are made of Hyphae
• Each Hypha is one cell, can have 1 or 2 nuclei
  free to move or not
• Body of Fungi is called Mycelium many hyphae
  tangled together
• Fruiting Body above ground reproductive part of
  mycelium

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More about their structure.

• The visible part of a fungus is only a very small
  part of the mycelium.

.most is underground
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Worlds Largest OrganismArmillaria ostoyae

• Covers 8.9km2 6.5 tons of biomass
• 2,400 years old
• Strawberry Mountain. Oregon

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FUNGI ADAPTATIONS

• Extracellular (external) digestion followed by
  absorption
• Some can be parasitic

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FUNGI REPRODUCTION

• Some reproduce asexually, some sexually
• Asexual reproduction
• Fragmentation/budding,
• Spores!
• Spores can be thick walled resist water loss
• (ie, the fungus won't dry out)
• Sexual reproduction
• hyphae fusion
• haploid haploid diploid

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Reproduction Summary
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Asexual Reproduction in Action

• Spores are being released into the air!

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Reproduction Summary
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Reproduction

• Sexual Reproduction
• 2 different mating types () and (-)
• Hyphae of opposite mating types meet
• Each Hypha forms a Gametangium
• Structure that makes gametes (haploid)
• 2 haploid gametes fuse make diploid zygote
• Meiosis takes place to make haploid org

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Classification of Fungi

• Classify by structure and reproduction methods
• All have different types of hyphae
• 1. Phylum Zygomycota Common Molds
• Ex Bread Mold
• 2. Phylum Ascomycota Sac Fungi
• Cup Fungi, Yeasts
• 3. Phylum Basidiomycota Club Fungi
• Mushrooms
• 4. Phylum Deuteromycota Imperfect Fungi
• Catch all Ex Penicillium

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Zygomycetes

• Zygote fungi
• Reproduce sexually asexually
• Formed from 2 different gametangium that fuse
• 2 Gametangium zygospore
• -Other hyphae, rhizoids, anchor the fungus
• Ex. Bread Mold (Rhizopus)

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Life Cycle of Phylum Zygomycota
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Ascomycetes

• Sac fungi
• Reproduce sexually asexually
• Spores (called ascospores) are made in a sac is
  called an ascus
• Conidiophores form and help disperse haploid
  spores
• Important fermenters
• Convert sugar to CO2 alcohol
• Ex. Yeasts (with no hyphae), powdery mildews,
  food molds

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Ascomycetes Life Cycle
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Basidiomycetes

• Club fungi
• Reproduce sexually asexually
• Forms a club shaped structure Basidia this is
  where spores are made Basidiospore
• Cap where reproduction takes place
• Ex. Mushrooms, puffballs, smuts

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Phylum BasidiomycotaLife Cycle
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Deuteromycetes

• Imperfect Fungi
• Reproduce asexually only
• Typical Molds
• Penicillin

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MUTUALISTIC FUNGI

• 2 types
• a) Lichens
• b) Mycorrhizae

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• a) Lichens
• SYMBIOSIS of a fungus (usually an ascomycetes)
  with an algae OR a cyanobacteria

• The fungal partner benefits by getting sugars,
  its only nutrients, from the algae which
  photosynthesize.
• The algal partner gets protection as the fungi
  normally forms the outer surface.

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• b) Mycorrhizae
• Fungus Plant
• Hyphae grow on
• roots of plant
• How does each benefit?

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Ecology of Fungi

• Fungi are heterotrophic decomposers
• Saprobes fungi that obtain food by breaking
  down dead and decaying orgs
• Can be decomposers good for nutrient cycle
• Need this to maintain life!
• Can be predators
• Some fungi poison and decompose worms which feed
  on them

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Ecology Cont.

• Disease Some Fungi are Pathogenic
• Plant diseases Rusts, Root Rot
• Animal diseases
• Ringworm, Yeast infections, Athletes Foot