Fungi

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Fungi
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Fungi

• Eukaryotic organisms
• Heterotrophic
• Contain the polysaccharide chitin in their cell
  walls
• Where once considered part of the plant kingdom
• Evolved close to 900 million years ago

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Classification of Fungi

• Over 70000 species have been described
• Estimated to have over 1.5 million species total
• Some phyla include
• Mastigomycota water moulds, chytrids
• Zygomycota moulds (bread moulds, dung moulds)
• Basidiomycota mushrooms, cap fungi
• Ascomycota yeast, morrels, truffles

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Fungi vs. Plants
Similarities Similarities
Eukaryotic, cell walls, anchored in soil or substrate Eukaryotic, cell walls, anchored in soil or substrate
Reproduce asexually, sexually or both stationary Reproduce asexually, sexually or both stationary
Differences Differences
Plants Fungi
One nucleus per cell Multiple nuclei
Autotrophs Heterotrophs
Starch for energy storage Little or no energy storage
Have roots No roots
Cellulose in cell walls Chitin in cell walls
Some reproduce by seed None reproduce by seed
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Fungi nutrition

• Feed by extracellular digestion
• As hyphae grow across its substrate, digestive
  enzymes are released
• Macromolecules are broken down into smaller
  molecules
• Smaller molecules are then absorbed into the
  hyphae

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Fungal Anatomy
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Fungal Anatomy

• Most fungi are invisible to the eye, as most of
  the fungus is in the soil or substrate
• Some become visible when we see their fruiting
  bodies (eg. mushroom caps)
• Mycellium networks of hyphal threads.
• Some fungi are the largest organisms on earth (an
  area of 2200 acres/ 8.9km2)

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Importance of Fungi

• Symbiosis symbiosis is two different species
  each depending on eachother
• Trees have fungi living in close quarters to
  their roots
• Hyphae absorb minerals/nutrients, and release
  them to the roots
• Fungus benefits by absorbing sugars and amino
  acids from the plant
• Relationship is call mycorrhiza (hyphae/roots)

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Mycorrhiza
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The fungus Aspergillus glaucus growing on bread
in a compost heap.
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Aspergillus fungus The fungus is made up of
fungal threads (hyphae, grey) with conidiophores
(fruiting bodies, brown) at the tip.
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Candida albicans fungus Cells
of the yeast- like fungus Candida albicans. This
fungus is a cause of yeas infections
(candidiasis). It is normally present on human
skin and on the mucous membranes of the mouth,
respiratory and intestinal tracts and the vagina.
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Ergot Ingestion of ergot causes poisoning
(ergotism) in animals and humans, which can be
fatal. Symptoms can include vomiting, gangrene
and hallucinations. A number of medical drugs, as
well as LSD, are derived from ergot
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Dermatophyten - This fungus is the cause of
athlete's foot (tinea pedis) and scalp ringworm
(tinea capitus). Both of these contagious skin
infections are spread by the fungus's spores
(orange). Also seen here are the fungus'
thread-like hyphae structures (green).
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MildewThe fruiting bodies of a fungus
growing in a compost heap. Compost is made by
allowing a heap of vegetable trimmings, non-
seeding weed plants and grass mowings to degrade.
The resulting brown, crumbly compost is dug into
soil to provide plants with nutrients.
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References

• Pictures from
• http//www.eyeofscience.de/
• www.thecapcrew.ca
• http//www.apsnet.org/education/illustratedglossar
  y/PhotosI-M/mycorrhiza.htm