The Fungi
(the one everyone wants to ask
to TWIRP?)
Main Ideas
I.
II.
III.
Characteristics of Fungi
Fungal Forms
Classification of Fungi
I. Characteristics of Fungi
A.
Made of eukaryotic cells
1.
2.
3.
Eukaryotic cells have a nucleus (prokaryotic
cells do not)
Animal and plant cells are also eukaryotic
Fungal cells have a cell wall (animal cells do
not).
I. Characteristics of Fungi
B.
Release exoenzymes into their
surroundings
1.
2.
3.
Fungi digest 1st, then ingest (we ingest, then
digest)
This allows the fungi to be decomposers
Fungi DO NOT PHOTOSYNTHESIZE – they
must obtain food from another source
(“heterotrophs”).
I. Characteristics of Fungi
C.
Made of hyphae – microscopic tubular filaments
composed of repeating cells.
1.
Hyphae grow and increase a fungus’s
surface area.
2.
A mass of interwoven hyphae is called a
mycelium (plural = mycelia)
3.
Mycelia are usually beneath the surface
4.
Mycelia can be massive
The “Humongous Fungus” of
Oregon - Armillaria ostoyae



Covers an area
equivalent to
1,600 football
fields!!
At least 2,400
years old!!
Estimated to
weigh hundreds
of tons!!
I. Characteristics of Fungi
D.
Reproduce through spores
1.
2.
3.
4.
Can be produced asexually and/or sexually
Fruiting body – structure built for dispersing
spores
Spores dispersed mainly through wind
Asexual stage = Imperfect stage
Sexual stage = Perfect stage
Main Ideas
I.
II.
III.
Characteristics of Fungi
Fungal Forms
Classification of Fungi
II. Fungal Forms
A.
Yeast
1.
2.
Some fungi exist only as yeast – others can
exist either as yeast or mycelia depending
on conditions
Yeast reproduce asexually by budding
II. Fungal Forms
A.
Yeast (cont.)
3.
Examples: baker’s yeast (Saccharomyces
cerevisiae)
-human yeast infections (Candida albicans)
4.
Uses in biotechnology
a.
Fermentation
b.
Study of molecular genetics in
eukaryotes.
II. Fungal Forms
B.
Molds
1.
Rapidly growing, asexually
reproducing fungi
2.
Can spoil bread, fruits, and cheeses
3.
Importance in biotech:
a. Fermentation
b. Penicillin
II. Fungal Forms
C.
D.
E.
F.
Mushrooms
Cups
Shelf Fungi
Puffballs
Main Ideas
I.
II.
III.
Characteristics of Fungi
Fungal Forms
Classification of Fungi
III. Classification of Fungi
A.
Saprophytes
1.
Feed on dead organic matter – the
decomposers
2.
Important to ecosystems for recycling
carbon, nitrogen, and other nutrients.
III. Classification of Fungi
B.
Parasites – are harmful to another organism
1.
Human – athlete’s foot, yeast infections,
ringworm.
2.
Over 70% of plant diseases are fungal (eg.
Dutch Elm Disease)
3.
Can also infect other microbes!
http://www.youtube.com/watch?v=jOwCOLf0IRU&feature=related
III. Classification of Fungi
C.
Mutualists – are beneficial to another organism
1.
Lichen – association of a fungus with algae
III. Classification of Fungi
C.
Mutualists (cont.)
2.
Mycorrhizae – association of a fungus with
plant roots
a. fungi “extend the reach” of plant roots
b. nearly all plants have mycorrhizae
c. plants get more minerals from soil; fungus
gets organic nutrients from plant