Characteristics of Fungus
•Eukaryotes.
•Have cell walls.
•Heterotrophs that feed by absorbing
their food.
•Use spores to reproduce.
Cell Structure of Fungus
•Fungi range in size from tiny yeast to large
multicellular fungi.
Yeast
•Cell of all fungi are
surrounded by cell walls.
•Hyphae make up most
fungi. They are branching
and threadlike fibers and
make up the body of the
fungus.
•Substances move quickly
through hyphae.
Important Parts of
Fungus
•Cap
•Gills
•Stalk
•Hyphae
•Underground hyphae
•The way a fungus looks depends
on how its hyphae are arranged.
Fairy rings are an
example of just how
strangely the hyphae of
fungus can arrange
itself!
•Fungi absorb food
through hyphae that
grow into a food
source.
•The hyphae ooze a
digestive chemical that
makes the food easy to
suck up (mushy- yuck).
•Some feed on dead
organisms.
REPRODUCTIVE STRUCTURES
ASEXUAL & SEXUAL SPORES
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REPRODUCTION
• Most fungi reproduce Asexually
and Sexually by spores
• ASEXUAL reproduction is most
common method & produces
genetically identical organisms
• Fungi reproduce SEXUALLY when
conditions are poor & nutrients
scarce
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SPORES
• Spores are an adaptation to life on
land
• Ensure that the species will
disperse to new locations
• Each spore contains a reproductive
cell that forms a new organism
• Nonmotile
• Dispersed by wind
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Sexual Reproduction
12
SEXUAL REPRODUCTION
• Used when environmental
conditions are poor (lack
of nutrients, space,
moisture…)
• No male or female fungi
• Some fungi show
dimorphism
– May grow as MYCELIA
or a YEAST –LIKE
state (Filament at 25oC
& Round at 37oC)
Dimorphic Fungi
13
SEXUAL REPRODUCTION
Haploid 1n hyphae from 2 mating types (+ and -)
FUSE (Fertilization)
Forms a hyphae with 2 nuclei that becomes a
ZYGOTE
The zygote divides to make a SPORE
+
SPORE FORMS
14
ASexual Reproduction
15
THREE TYPES OF ASEXUAL REPRODUCTION
• Fragmentation – part of the mycelium
becomes separated & begins a life of
its own
• Budding – a small cell forms & gets
pinched off as it grows to full size
– Used by yeasts
• Asexual spores – production of spores
by a single mycelium
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Reproduce by spores
• Spores may be Formed:
– Directly on hyphae
– Inside sporangia
– On Fruiting bodies
Penicillium
hyphae
Amanita fruiting body
Pilobolus sporangia
ASEXUAL REPRODUCTION
Fruiting Bodies are modified hyphae that
make asexual spores
An upright stalk called the
Sporangiosphore supports the spore case
or Sporangium
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ASEXUAL REPRODUCTION
Types of Fruiting
Bodies:
Basidia
Sporangia
Ascus
Sporangia
Basidia
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Hyphal growth from spore
Germinating spore
mycelium
•
•
Mycelia have a huge surface area
More surface area aids digestion & absorption of food
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Classification of Fungi
Club Fungi
Sac Fungi
Zygote
Fungi
Club Fungi
•Produce spores in
reproductive structures
that look like clubs.
•Some like puffballs are the
most poisionous.
Sac Fungi
•Produce spores that look like
long sacs (but you can see
that in these pictures).
•Yeasts, morels and
yes…TRUFFELS.
Zygote
Fungi
•Can survive harsh
environmental
conditions.
•Fruit and Bread Molds.
h] of Fungi
Three Groups
• Mushrooms
• Molds
• Yeast
Mushrooms
• Mushrooms are multicellular fungi
• They produce thousands of spores
• The main bosy of this fungus is under the
ground in a mycelium form
– Mycelium is the vegetative part of a fungus,
consisting of a mass of branching, thread-like
hyphae.
Molds
• Molds are simple organisms that are made up
of two parts
– The filaments - a slender threadlike object or fiber
– The spore structures
• They are hairy, fuzzy fungus that grows on
spoiled food
• They are multicellular.
• Penicilliium is a very common mold that is
used today in the “wonder drug” called
penicillin
Yeasts
• Is a unicellular fungus
• That is larger and more complex than a
bacteria cell. It is a Eukaryotic Cell
• This can be used in the making of
– Bread
– Alcohol
– And carbon dioxide
The Role of Fungi in Nature
Harm
Food and
Fungi
Benefits
Environment
and
Recycling
Environment and Recycling
• Fungi are the major decomposers of nature;
they break down organic matter which would
otherwise not be recycled.
• Aiding the survival of species from other
kingdoms through the supply of nutrients,
fungi play a major role as decomposers and
recyclers in the wide variety of habitats in
which they exist.
Food and Fungi
• Fungi may be the food, or may make the food
edible following processing. Processing may
make it possible to consume the foodstuff by
adding, modifying or removing components.
• Fungi are a common contributor to the
processing of foods.
Benefits and Harm
• Beneficial Effects of Fungi
– Decomposition - nutrient and carbon recycling.
– Biosynthetic factories. Can be used to produce drugs, antibiotics,
alcohol, acids, food (e.g., fermented products, mushrooms).
– Model organisms for biochemical and genetic studies.
• Harmful Effects of Fungi
– Destruction of food, lumber, paper, and cloth.
– Animal and human diseases, including allergies.
– Toxins produced by poisonous mushrooms and within food (e.g., grain,
cheese, etc.).
– Plant diseases.