Transcript Fungi - Wild about Bio

Fungi
Unit 8- Chapter 31
What is a Fungi?
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Usually multicellular
Above ground structures (mushrooms)
Breakdown organic material and recycle
nutrients
Tiny fraction causes disease
Plant roots depend on them to help with
nutrient absorbtion (symbiotic relationship)
Nutrition and Lifestyle
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Heterotrophs
Do not ingest food
Secrete enzymes (exoenzymes) into their
surroundings, which break down complex
molecules for the fungi to absorb.
Some species are:
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Decomposers: break down non living material (logs, wastes
from animals, animal corpses
Parasites: absorb nutrients from host cells
Mutualistic symbionts: absorb nutrients from host cell but the
host cell isn’t hurt but rather benefits from the fungi
Body Structure
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Single cell fungi = yeast
Most are multicellular
Hyphae: A filament that
collectively makes up the
body of a fungus.
Chitin: a strong but
flexible polysaccharide
that makes up the cell wall
of fungi.
Mycelium: the branched
network of hyphae that
allows for feeding
Specialized Hyphae
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Septa: pores large
enough for organelles to
flow from cell to cell
Coenocytic: lack pores,
continuous cytoplasm
with many nuclei.
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Haustoria: enables
penetrating of a host cells
tissue.
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Mycorrhizae: symbiotic
relationship with plant roots.
Sexual Reproduction
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Hyphae from 2 different mycelia release sexual
signaling molecules (pheromones)
Both Hyphae extend toward the source of pheromones
and fuse together.
“Compatibility Test” prevents haphae from fusing with
hyphae from the same mycelium.
Union of cytoplasm (plasmogamy)
Hours, days, centuries later the haploid nuclei from
each parent fuse together = diploid cell (karyogamy)
Meiosis occurs and restores cells back to haploid form
producing spores
Asexual Reproduction
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Clones are produced by mitotic production of
spores
Spores are spread through air, wind, water
Molds (kitchen products) produce spores
Yeast (moist habitats) simple cell division
Fungal
Phylogeny
Phylum Chytridiomycota
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Aka Chytrids
Earliest of all fungi
Unique flagellated spores (zoospores)
Either decomposers or parasites
Phylum Zygomycetes
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Fast growing molds
Aka Zygote Fungi
Some are parasites or commensal
symbionts (one benefits)
Coenocytic hyphae
Parasites = Mycrosporidia
Phylum Glomeromycota
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Glomeromycetes
Form endomycorrhizae with plant roots
Hyphae branch into treelike structures
Phylum Ascomycetes
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Production of sexual spores (asci)
Aka Sac Fungi
Fruit bodies (ascocarps)
Decomposers of plants
Symbiotic relationships with plant roots and
green algae (lichen)
Asexual reproduction: Produce asexual
spores (conidia) where the spores are
released into the wind and attach to a hyphae
Sexual reproduction: Fusion of 2 different
mating types, asci produces ascospores
which are later released by ascocarp.
Phylum Basidiomycota
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Basidiomycetes
Mushrooms, shelf fungi, aka club fungi
Some molds and parasites (rust and smuts)
Decomposers of wood and plant material
Sexual reproduction
Fruiting bodies (basidiocarps) ex:
mushroom
Mushroom cap releases the basidiospores
Asexual reproduction is less common
Impact of Fungi
Decomposers:
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Plants (cellulose)
Keep ecosystems
stocked with
inorganic nutrients
Balance carbon,
nitrogen, and other
essential elements
recycle
Symbionts:
1. Mycorrhizae- relationship with
plant roots
- Helps absorb nutrients that root
couldn’t normally get on its own.
2. Fungus/Animal Symbiosis-break
down plant material in the guts of
animals.
-Ants take leaves to fungi so they
can break it down to a material in
which the ants can digest.
3. Lichens- surface hugging carpet
found growing on rocks, trees,
roofs, etc.
-fungi + green algae or
cyanobacteria
-”dual organism”
-sensitive to air pollution
Pathogens:
-About 30% (mostly in plants)
-Affect agriculture
-When infected in
animal/humans (mycosis)
-Ringworm
-Athletes foot
-Black mold
Practical use of Fungi
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Mushroom for food
Fungi is used to ripen some cheeses
Fungi are used to produce citric acid in soft
drinks
Yeast are used for alcoholic beverages
Antibiotics for bacterial infections (penicillin)
Medical research