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FungiFungi
The multicellular eukaryotic organisms that feed on dead or decaying organic material
Outline of TodayOutline of Today’’s lectures lecture
� I. Fungi• Key concepts• Representatives• Characteristics• Classification• Roles of fungi
� II. Mitosis & Meiosis
� III. Life cycle : 1. Animal 2. Human 3. Fungi
Key Concepts:Key Concepts:
� Fungi are heterotrophs
� Fungi secrete enzymes that digest food outside
their body, then fungal cells absorb breakdown
products (extra-cellular digestion)
� Fungi do not ingest food and Fungi cannot move
� Most fungi are multicelled
� A portion of the fungal hyphae becomes
modified and forms a reproductive structure
� Many fungi are symbiotic with other organisms
Fungal Species from Fungal Species from Southeastern VirginiaSoutheastern Virginia
Purple Coral
Fungus ClavariaRubber Cup
Fungus Sarcosoma
Fungal Species from Fungal Species from Southeastern VirginiaSoutheastern Virginia
Big Laughing
Mushroom Gymnophilus
Trumpet Chanterelle
Craterellus
Fungal Species from Fungal Species from Southeastern VirginiaSoutheastern Virginia
Scarlet Hood
Hygrophorus
Characteristics & ClassificationCharacteristics & Classification� Mode of Nutrition
� Heterotrophs
� Saprobes
� Parasites
� Major Groups (100,000
species)
Chytrids
Glomeromycetes
� Zygomycetes (Zygomycota)
� Sac fungi (Ascomycota)
� Club fungi (Basidiomycota)
� Life Cycles
� Spores
(reproductive
cells)
� Mycelium (mesh
of branched
filament)
� Hypha (filament)
hyphae (plural)
Chytrids (1,000 species)
25 μμμμm
25 μμμμm
Zygomycetes (1,000 species)
Glomeromycetes (160 species)
Ascomycetes (65,000 species)
Basidiomycetes (30,000 species)
Hyphae
Fungal
hypha
Asexual Reproduction inAsexual Reproduction inRhizopus stoloniferRhizopus stolonifer
Sexual Reproduction of Fungi Sexual Reproduction of Fungi
Club fungi
Sexual Reproduction of Fungi Sexual Reproduction of Fungi
Slide 4
Fig. 24.4, p. 395
nuclear fusion
After nuclear fusion, the club-
shaped structure (now 2n) will
produce and bear haploid spores
at the four tips of the cell.
meiosis
cytoplasmic
fusion
Diploid Stage
Haploid Stage
Club-shaped
structures
having two
nuclei (n + n)
form at the
margin of each
gill.gills
After cytoplasmic fusion, a
“dikaryotic” (n + n) mycelium
gives rise to spore-bearing
bodies (e.g., mushrooms).
cap
stalk
spore (n)
Spores are released.
Each germinating spore
gives rise to a hypha
that grows and becomes
a branching mycelium.
hypha
hypha in
mycelium
Roles of Fungi
�Decomposers &
recyclers of nutrients
�Food
�Medicine
The antibiotic
penicillin was
first isolated from
the fungus
Penicillium
�DiseasesCrops, fruits, food
Club FungiClub Fungi
Light-red
coral fungus
Ramaria
Shelf fungus
Polyporus
Club Fungi MushroomsClub Fungi Mushrooms
Amanita muscaria
- hallucinogenic
Amanita ocreata
- fatal
LichenLichen
� Symbiosis
�Lichen
Lobaria oregana
II.II. Mitosis & MeiosisMitosis & Meiosis�Mitosis – A type of eukaryotic cell division, which results two daughter cells that are genetically identical to the parental cell.
�Meiosis - A type of eukaryotic cell division,
which results four daughter cells that have
only a half number of the parental cell’s
chromosomes.
Mitosis
Meiosis
III.III. Life CycleLife Cycle
�Life cycle – the events in the life of an organism from one generation to the next.
�Life cycle: 1. Animal 2. Human 3. Fungi
Animal Life Cycle