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What is a Fungus?
Kingdom Fungi
• eukaryotic heterotrophs
• Most are multicellular
• Have cell walls made of chitin
• Some are saprophytes (decomposers), others
parasites (harm other organisms) while others
still are symbiants (live on but do nor harm other
organisms).
• All use extracellular digestion. They produce
powerful digestive enzymes that they secrete
into their food, then absorb the nutrients into
their cells.
• All Reproduce through some form of
Sporulation (although some Fungi species can
also reproduce by budding and fragmentation)
• the body a typical fungus is made up of tangled
filaments called a mycelium. Each individual
filament is called a hyphae.
• Yeast are an exception (they are unicellular)
Hyphae
mycelium
• Fungi can be parasitic:
– Cordyceps fungus
– Ringworm
– Athlete’s foot
– Tomato blight fungus
Athlete’s footRingworm
Tomato
blight
fungus
Mycorrhizae
• Fungi form symbiotic realtionships with the
roots of some plants
Fungus Asexual Reproduction
• Spores produced in sporangia (sporulation)
• fragmentation
Orange peel mold
More spores
Spores and budding
Fungus Sexual Reproduction
• Hyphae of two different mating types
(‘+’ and ‘-’) can fuse to form a gamete forming
structure (gametangium).
• Two fused gametes form a diploid zygote
nucleus which then divides by meiosis.
Phylum Oomycota: Protistlike
FungiThe Water Moulds and Mildews
• Aquatic
• Parasitic on land plants and fish.
• Cell walls contain cellulose not chitin.
• Spores swim using a flagellum (only fungus with motile spores)
Plasmopara viticola,
the downy mildew of
grapes. Almost wiped
out the European wine
industry.
Phylum Zygomycota
Common Molds
Most species are Terrestrial Organisms found primarily in Soil
• Black Bread Mold, Rhizopus stolonifera, not only grows on Bread, but anywhere there is water and nutrients.
• Common Molds life cycles includes both Asexual and Sexual Stages.
Phylum Ascomycota: Sac Fungi
• Largest phylum
• Include yeasts, morels and truffles
• Saprobes that feed off of dead organisms
• Sexual and asexual reproduction
morels
Budding
yeast
Type of
cup
fungus
Ergot
• LSD itself has origins in a naturally occurring fungal disease of rye
grains, ergot. Although this fungus is the source of drugs useful in
treating migraine and hemorrhaging, it is also the notorious cause of
hallucinations & temporary insanity in people who inadvertently eat
affected grain. In medieval times, French peasants suffering from
ergot poisoning were thought to be consumed by holy fire- St.
Anthony's Fire- because they frequently complained of excruciating
sensations of burning, not to mention infections of gangrene caused by
the interruption of circulation in the limbs. Though the control of
ergot, by burning infected crops, is relatively simple, incidents of ergot
poisoning have been reported as late as 1951.
Phylum BasidiomycotaClub Fungi
• “mushrooms”
• Saprobes that live off of dead organisms
• Mushrooms, toadstools, bracket fungi, puffballs
annulus
Stalk
(stipe)
Gills (arrow
shows spores)
Cap
(pileus)
mycelium
Poisonous Mushrooms of Nova Scotia
Squirrels & other rodents often
feed on Fly Agaric, but this does
not mean the fungus is edible by
humans. While ingestion of a
single mushroom may cause no
lasting effects, consumption of
ten or more can be FATAL.
Magic MushroomsMAGIC" MUSHROOMS
REALLY AREN'T MAGIC AT
ALL.
In fact, their alarming effects are the
harsh and sometimes not so short
result of disruptive chemical
interference with the body's nervous
system.
It is a criminal offence to gather,
possess or sell any of them.
Phylum Deuteromycota –
Imperfect Fungi
• Cannot be placed in any other phyla because
their sexual reproduction has never been
observed
• Resemble many of the other phyla
Athlete’s foot
Ringworm
Tomato
blight
fungus
Penicillium
Fungi in Nature
Ecological Significance
• The principal role of fungi is to decompose and
recycle living material
Symbiotic Relationships
• Lichens are symbiotic partnerships between a
fungus and a photosynthetic organism. There are
many other examples
Lichens • Made up of 2 organisms: sac fungi and algae
• Live on rocks, trees and soil
• Food for some animals
• Help in the formation of soil by breaking down rock.
Mr. Fungi meet Mr. Algae
Lichen Examples
Crustose lichens:
finely textured,
coloured patches
on rocks and trees.
Fruticose lichen:
Lacy and branched.
The copper brown
lichen blows around
the Arctic tundra.
Reindeer moss.
Foliose lichen:
Lobed or leaf-
like lichen. The
are attached to
rocks and trees
by hyphae.
Fungi and Human Life
• Bread and alcohol industries rely on yeast.
• Many mushrooms are a delicacy however some
are poisonous.
• Potato Blight & Wheat Rust are notable diseases
of plants.
• Human diseases include ringworm, athletes foot,
mouth, urinary tract and vaginal infections.
• Some fungi kill other organisms
Dutch Elm Disease:
• Spores are spread to healthy elms by a
burrowing beetle. The new spores germinate
under the bark.