AP BIOLOGY 11
14. The Fungi
Mycology
Go to:
http://www.fungiphoto.com/CTLG/SYS1/C.clr.html
Characteristics
• Eukaryotic
• Heterotrophic by absorption-feeding, releasing
digestive enzymes directly into the surrounding
environment
• Must live in contact with their food which is often
decaying
• Cell walls made of Chitin (not cellulose as found
in green plants)
• May contain centrioles
• May be unicellular, colonial, or multicellular
Body Plan
• Fungi all consist of
three basic body parts
A) Mycelium
• Mass of thread like
hyphae that grow into
media - body of
organism
• Used for digestion and
absorption
Go to: http://www.aw-bc.com/campbell/
Body Plan
B) Fruiting Bodies
• Reproductive (asexual
usually) structures
used for both
reproduction and
dispersal of the species
• Located above the
ground
• Ex. A mushroom
Body Plan
C) Spores
• Haploid structures
produced by meiosis
• Asexual structures
used for reproduction
• Land adapted for
species dispersal by air
Spores on Penicillium sp.
Hyphae
1. Descending hyphae
(rhizoids) used for
extracellular digestion and
absorption of nutrients form the mycelium (body
of the organism). Also
involved in sexual
reproduction by
production of gametes
which fuse to form a
zygote.
Hyphae
2. Ascending Hyphae
• These grow up from
mycelium and produce
sporangium (n) which
produces multitudes of
haploid spores by mitosis.
• These are air borne so the
ascending hyphae raises
them as high as possible
Hyphae
3. Transverse Hyphae
(stolons)
• These typically grow
parallel to soil and are
used to asexually establish
satellite colonies
• Can also be be used for
sexual reproduction
• All multicellular fungi
show these three types of
specialized hyphae which
illustrates land adaptation
http://upload.wikimedia.org/wikipedia/commons/thumb/6/66/Penicillium.jpg/300px-Penicillium.jpg
Fungal Life Cycle
http://occawlonline.pearsoned.com/bookbind/pubbooks/campbell6e_awl/chapter31/deluxe.html
Fungal Life Cycle
Spore Dispersal
• Insects (e.g. fruit flies
from one fruit to another)
• Eaten and defecated by
animals
• Wind or air-born (e.g.
bread mold)
• Fluid filled “bulb” with
spore packet propels, like
a canon, to area where
animals will eat. (e.g.
Pilobolus – “hat thrower”)
Fungi Classification
• Fungi were initially classified as plants so
retain many plant related names.
• Classified based upon their distinctive
reproductive structures (sexual or asexual)
• Three main groups called Divisions (rather
than phyla). Currently, seven fungal divisions are
proposed Zygomycota, Ascomycota, Basidiomycota
Division Zygomycetes
• Mostly terrestrial living in soils and acting as
decomposers.
• Good at breaking down animal waste (feces)
• The common bread mold Rhizopus sp. is used
as a typical example of this division.
www.rogers.k12.ar.us/users/ehutches/tigerbreadmold1.jpg
Division Ascomycetes
• Largest group of
fungi
• All produce two
types of spores:
A) Ascospores: sexual
spores within a
specialized structure
called an Ascus
Ascospores inside an ascus of a
cup fungus
Division Ascomycetes
B) Conidiospores
• These are asexual
spores produced inside
a sporangium called a
Conidia
• Located on ascending
hyphae
Ascomycetes Life Cycle
Division Ascomycetes
Truffles from Oregon
• Include:
• Sac fungus,
lichens (fungus
portion), truffles,
Penicillium,
Aspergillius
Mold
Division Ascomycetes
Various lichen types
Division Ascomycetes
Cup Fungus
Penicillin sp.
Division Basidiomycetes
• Most advanced
multicellular fungi
• Reproduce asexually
with basidiospores
produced from
sporangia called
basidia
• Examples include
mushrooms and
toadstools
Division Basidiomycetes
• The mushroom is a typical
basidiomycetes
• Ascending hyphae grow
together to form solid mass
that allows basidia to be
raised much higher
• What we call the mushroom
is really the fruiting body of
the organism properly called
a Basidiocarp.
Basidiomycota Life Cycle
Division Basidiomycetes
• The cap covers and
supports the gills.
• The gills are made
from the end of the
ascending hyphae
which terminate as
basidia.
• The gills provide
massive surface area
for spore development
Division Basidiomycetes
• The basidia are club
shaped structures that
asexually produce the
basidiospores.
• These spores are
released and
distributed by air
promoted by being
elevated by the
mushroom stalk.
scarab.cordley.orst.edu/shrooms/webpages/text/images/ama_pac_micro.jpg
Division Basidiomycetes
• Like most fungi, the
basidiomycetes are
decomposers
• They are remarkable
for their rapid growth
in favorable conditions
bcmushrooms.forrex.org/ntfp/images/introduction/diagrams/mushroom.jpg
Other Basidiomycetes
Earth Star
Puffballs
Bracket Fungi
Importance of the Fungi
1. Decomposers
• Along with bacteria,
they are the worlds
major recyclers of
organic compounds
• Can tolerate
environments bacteria
can’t ex. High acid
Importance of the Fungi
2. Diseases
A) Plants
• Plants are more
susceptible to fungal
infections than
animals
• Most common
includes rusts and
mold infections
Importance of the Fungi
B) Animal Diseases
• Most fungi are
opportunists in
animals
• Most common
infections are to the
skin and mucous
membranes. Ex.
Candida and Athletes
foot
www.healthegoods.com
3. Food: Many fungi are
edible
Importance of the Fungi
Truffles
Mushrooms
Importance of the Fungi
4. Fermentation
• Yeast convert sugar to
alcohol and CO2 by
fermentation.
• This is widely used for
making wine and beer
but is also essential in
making bread and
other doughs that must
rise by yeast.
www.alientravelguide.com
Importance of the Fungi
5. Antibiotics
• Many antibiotics come from
molds.
• Antibiotics are competitive
inhibitors produced by
certain fungi and bacteria
• This Penicillin disk on the
side of the Petri disc is
inhibiting bacteria
http://img301.imageshack.us/i/s58dryh9.gif/#q=fleming%20antibiotics
Importance of the Fungi
6. Symbiotic Fungi
A) Mycorrhizae
• These are fungi that grow
with plant roots
• This greatly increases root
surface area for absorption
• In return, fungi gets
organic nutrients
• Found in 95% of all plants
Importance of the Fungi
B) Lichens
• Symbiotic relationship between
a fungi (ascomycetes) and
filamentous green algae
• Fungi provides a home and
traps water and minerals for the
algae
• Algae provides food (organic
compounds) for the fungus
• Ecologically important as
pioneer organisms
•
(end show)
FUNGI are just FUN GUYS!