FUNGI
Eukaryotic cells
Most are multi-celled
Some are uni-cellular
Heterotrophs
Live in moist, warm areas
Have Cell Walls
FUNGI
• Fungi used to be classified in the plant kingdom
because, like plants, many fungi grow anchored in soil
and have cell walls.
• The basic structural units of multicellular fungi are their
threadlike filaments called hyphae, which develop
from fungal spores.
Some hyphae anchor the fungus, some invade the food
source, and others form fungal reproductive structures.
Spores
Bread Mold
Hyphae
Mycelium
Fungal Structure
• Fungal body
– mycelium
• thread-like cells
• Network of hyphae
• Cell wall
– Made of chitin
• polysaccharide
• just like insect
exoskeletons
Internal structure
• Eukaryotic cells
– long, thread-like cells
• filamentous
– incomplete divisions
between cells
• septum
– multiple nuclei
Modes of Nutrition
• Heterotrophic
fungal hypha
– secrete digestive enzymes
– feed by absorption
• parasites
– feeding on living creatures
• predators
– paralyzing prey
plant cell
membrane
• saprobes (decomposers)
– breakdown dead remains
plant
cell wall
plant cell
Reproduction
• Asexual
– budding in yeast
– fragmentation
– zygospores
• spread by wind, water, animals
• Sexual
– joining of haploid hyphae
– ascospores
Zygomycota
(Bread & Fruit Mold)
Decomposers
Hyphae without septa
Reproduction: Asexual- zygospores
Sexual- hyphae fuse
Zygomycota
(Bread & Fruit Mold)
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•
Ascomycota
sac fungi
Largest phylum of fungi
Saprobes, parasites, pathogens.
Yeast are microscopic, while most other
Ascomycota are macroscopic
• Produce sexual ascospores in sac-like
structures called asci
Basidiomycota
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•
•
•
Include mushrooms, puffballs, shelf fungi, stinkhorns
macroscopic forms -saprobes.
microscopic forms - pathogens & parasites.
Form sexual spores called basidiospores found in the
gills
Deuteromycota. These fungi are often termed “fungi imperfecti”
because sexual reproduction has never been observed in them. They lack the
structures for sexual reproduction, and produce their spores asexually.
Imperfect Fungi
Around 25,000 additional
fungus species are grouped
in this phylum.
Daniel
Members include
Trichophyton (Athlete's foot),
Penicillium notatum (Penicillin),
Candida albicans ("Yeast“ infections)
Ecological Roles
• Decomposers
– recycle nutrients
• Symbiotic Relationships
– lichen
• fungi + algae (Mutualism)
– cyanobacteria or green algae
• pioneer species in ecosystems
• makes soil from bare rock
– mycorrhizae
• fungi + plants
• live in & amongst plant roots
• enables plants to absorb more water & nutrients
Mycorrhizae
• Critical role in plant growth
– extends water & nutrient absorption of roots
without
mycorrhizae
with
mycorrhizae