Fungi
•Multicellular except for yeast
•Cell walls made of chitin (study guide question 3)
•Some with multinucleate cells and incomplete cell walls (see next slide)
•Mycelium – body of the fungus (study guide question 2 & 4)
•Hyphae – filaments that make up the mycelium (study guide question 2 &
4)
•Classified by method of sexual reproduction; can also reproduce
asexually
• -Myco or -mycete = fungi
•Heterotrophic by absorption
•Decomposer (saprophyte) - feeding on dead and decaying
organisms or parasitic – living in or on another organism, possibly
causing disease (study guide question 5)
•NO chlorophyll! NOT photosynthetic (study guide question 1)
Fungal hyphae showing some with cell walls and some without
Note the pore through the cell wall allowing cytoplasm to move
from cell to cell to bring nutrients from one end of the organism to
the other
Question 2 & 4 in the study guide:
Kingdom Fungi
Three phyla of fungi, based on method of sexual
reproduction:
•Zygomycota
•Basidiomycota
•Ascomycota
Protist that gave
rise to the fungi
•Use the information in the following slides to complete
the table in your notes.
•Note that some fungi are classified as Deuteromycota or Fungi Imperfecti because the method
of sexual reproduction has not been discovered. When it is, they will be placed in the
appropriate phylum.
Summary of Fungi
Reproduction
Spore –
reproductive cell that
is resistant to
environmental
conditions and that
can develop into an
adult without fusion
with another cell
(asexually)
Zygomycota
•Fungi that reproduce with
zygosporangia – structures resistant to
freezing and drying, allowing the organism
to live through “tough times”
•Have no walls in their hyphae
(multinucleate cells)
•Ex) Pilobus (top picture) can aim its
sporangia toward light where grass is
likely to be growing, then shoot spores to
the grass. Important because they
depend on grazing animals, like cows, to
scatter the spores through feces.
•Ex) Rhizopus stolonifer - black bread
mold (bottom picture); diagram p. 485
Basidiomycota – club fungi
•Fungi that reproduce with basidia (an external club-like
structure found under the cap of a mushroom) that bear
spores
•Hyphae are divided by walls, but usually walls are
incomplete so cytoplasm can still move from cell to cell;
important in “eating”
•Ex) mushrooms, puffballs, rusts, smuts, shelf fungi
mushroom
Shelf
fungus
Stinkhorn fungus
Fairy ring – results from the outward growth in
all directions of a basidiomycete (mushroom);
the structures visible above the ground are the
reproductive structures; the body of the fungus
(mycelium) is in the ground
Examples of basidiomycetes
Rusts, smuts, & ergots
Fun Fungi Fact:
Ergots – can cause
gangrene, nervous spasms,
burning sensations,
hallucinations, temporary
insanity, and death when
accidentally ingested
In 944 A.D. more than
40,000 people died in
France from ergot
poisoning. It contains one
of the active ingredients
found in LSD.
Some of the “witch hunts” of 17th century America have
been attributed to ergot poisoning as it is a common pest
in rye.
Oddly enough, it has been
used for medicinal
purposes in treating high
blood pressure and
stopping maternal bleeding
following childbirth
Ascomycota – sac fungi
•Fungi that reproduce with internal sac-like structures called
asci that are full of spores
•Hyphae are divided by walls, but usually walls are
incomplete so cytoplasm can still move from cell to cell;
important in “eating”
•Ex) cup fungi, yeast, morels, truffles (not chocolate ones!)
An edible
morel
Truffle – worth $600 a pound
Yeast budding
(study guide question 8)
Yeast are
ascomycetes
Budding –
asexual
reproduction
Mold
Note the zone of
inhibition around
this Penicillium
Penicillium - an ascomycete
commonly called “mold” that
naturally produces an antibiotic
bacteria
What color are fungi NOT? What is missing in the fungi that
would make them that color? (Hint: look at the autotrophic,
multicellular organism with cellulose in its cell walls surrounding
many of these fungi) Answer: Green, CHLOROPHYLL
HOW is that evidence that fungi are heterotrophic?
What is missing in the fungal cells that are present in the other
organism’s cells????
Answer: No cholophyll means no chloroplasts. No chloroplasts
means no photosynthesis. No photosynthesis means heterotroph.
Fungal Partnerships
Symbiotic relationship – one in which two species live together
in a close, long-term association
ex) mutualism – both benefit (mycorrhizae & lichens)
ex) parasitism – host organism is harmed, the parasite
benefits
ex) commensalism – one organism is neither harmed
nor benefits, the other benefits
Fungi are heterotrophic. Parasitic fungi penetrate a
living organism with specialized hyphae to allow the
fungus to absorb nutrients from its host.
Other fungi can prey on organisms that wander into its
path by trapping the prey with specialized hyphae
upon contact and then penetrating the organism with a
different type of hyphae (nematode caught by fungus)
Lichen – mutualistic
relationship between a
photosynthetic organism and
a fungus
- important pioneer
species, especially in primary
succession
Effects of mycorrhizae(word parts –
“fungus root”) on plant growth
Mycorrhizae – mutualistic relationship
between a fungus and a plant root
- the plant supplies the fungus with
carbohydrates while the fungus absorbs
phosphorus and other minerals from the soil and
passes them to the plant, which would be unable to
get these minerals without mycorrhizae
- fossilized plants have mycorrhizae,
showing that they probably couldn’t have moved on
to land without fungi!
Fun Fungus Fact: Most
mushrooms that grow at the base of
trees are actually the reproductive
structures of mycorrhizae
Plant without
mycorrhizae
Plant with
mycorrhizae
•Molecular evidence from comparisons of several
proteins and ribosomal RNA indicates that fungi
are more closely related to ANIMALS than to
plants.
Remember the chitin!!!!
Important Fungal Traits
Principal decomposers
Pioneer species
Pollution indicators (p. 492)
Nitrogen fixers
Symbionts
Antibiotic producers
Also, flavor cheese, make bread rise, used in beer brewing,
& wine making, as well as providing a food source for many
organisms (mushrooms!)