Fungi - Phsgirard.org

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Transcript Fungi - Phsgirard.org

Kingdom Fungi
Fungi Kingdom contains:
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Molds
Mildews
Rusts & Smuts
Yeasts
Mushrooms
Ecological Roles
• Decomposers
• Parasites
• Mutualistic symbionts
Trophic Level
• Saprophytic
• Parasitic
Indian Pipe is saprophytic
Fungal Roles
• Break down organic material returning
nutrients to the soil.
• Yeasts are useful in the making of
bread and fermented drinks.
• Human pathogens e.g. athlete's foot
and ringworm.
External Digestion
Extra-cellular digestion occurs by secreting enzymes into
environment and absorbing the nutrients produced.
Fungus Structure
Fungal Parts
Hypha - the vegetative
filament
Septum - perforated
cross walls
Mycelium - a mat of
interwoven hyphae
Why aren’t fungi classified as plants?
• Non-photosynthetic (Heterotrophic)
• Fungi cell walls are made of chitin
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• Plant cell walls are made of cellulose
• Fungi store their food as glycogen (like animals)
Plants and green algae store their food as starch
Life Cycle
Life Cycle
• Begins as a spore that grows when conditions are right
• Out of the spore wall grows a hypha
• The body of the fungus is made up of hyphal threads
collectively called the mycelium
• The mycelium grows in soil or within dead wood or living
organisms
• When growing conditions are favorable, the mycelium
develops fruiting bodies, e.g. mushrooms
• Fruiting bodies produce new spores.
Types of Asexual
Reproduction
• Forming spores at the end of the hyphae.
• Fragmentation- If the hyphe are broken, the
pieces will grow into complete new organisms.
• Yeasts reproduce by an asexual process called
budding. In this process, the yeast cell pinches
itself off to produce a small offspring cell.
Spores at the ends of hyphae
Budding
Sexual Reproduction
• Each of the four divisions of fungi
have different forms of sexual
reproduction
Fungal Classification
• Chitridiomycota – Primitive flagellates
• Zygomycota - Common bread mold
• Basidiomycota - Mushrooms, puffballs, rusts,
smuts, and stinkhorns
• Ascomycota- Mildews, yeasts, and truffles
(sac fungi)
• Deuteromycota – Ringworm, athletes foot
Fungi
Cladogram
Chitridiomycota
• Most primitive group
• Aquatic parasites (may be responsible
for global decline in amphibians)
• Only Fungi with flagella
Zygomycota
• Hyphae lack septa
• Asexual reproduction is by conjugation
Basidiomycota
• Underground hyphae intertwine and grow
upward to produce a mushroom.
• A "fairy ring" is actually a single organism. As
the hyphae expand outward, the mushrooms
grow around the outer edge. As long as
the organism survives, the circle of mushrooms
will be wider every year.
Fairy Ring
Stinkhorns
Puffballs
Smuts
Rusts
Rust Pathogenesis
Mushrooms
Mushrooms
Mushroom Life Cycle
Gills
Ascomycota
• Largest group of fungi
• Named for the reproductive sacs or Asci
that form near the tips of the hyphae.
• Ascospores are formed here and released
into the air when the ascus ruptures.
• These spores germinate to form new
hyphae.
Mildew
Truffles
Yeast
Candida albicans
Deuteromycota
Tinea Pedis
Tinea corporis
onychomycosis
Fungal Symbiosis
• Over 90% of plants have fungi associated with their roots.
• The fungus absorbs and concentrates phosphates for
delivery to the plant roots.
• In return, the fungus receives sugars synthesized by the
plant during photosynthesis.
Lichens
• A symbiotic association between a fungus and
a photosynthetic partner, usually green algae.
• The fungi hyphae provide
protection and hold
moisture while the
photosynthetic partner
provides food.
Lichens
• Green color is because of
the green algae cells
growing between the
hyphae of the fungus.
• The grey is a lichen
• The orange is a fungus
without algae
Lichen