Download FUNGI “Plants without chlorphyll”

FUNGI
“Plants
without
chlorphyll”
WHAT MAKES A FUNGUS A
FUNGUS???
1. We seldom see the living parts.
2. Uses branches of tubing to obtain nutrients.
3. Unlike a plant or an animal, there are no
differences in tissues or organs.
4. Lacks chlorophyll
5. releases powerful enzymes to break down
organic matter for nutrients
6. Plants have cellulose in cell walls whereas
fungi have chitin (which also forms the
exoskeletons of insects, crabs and lobsters)
Fungi
• Fungi structure – completely unique! No two are
structures are the same.
• Hyphae (singular, hypha) -- tiny threads of cytoplasm
surrounded by a plasma membrane and covered by a cell
wall
• Most fungi build cell walls out of chitin, a strong, flexible
polysaccharide that is also found in the external skeletons
of insects.
• The "mushroom" that you see above ground is the
reproductive structure of the fungus.
• most fungi = multicellular
• hyphae of fungus branch as they grow, forming a mat =
mycelium
• The mycelium functions as the feeding structure of a
fungus.
1. Mycelium
intertwined
hyphae which
makes up the
body of a
fungus
2. Hyphae individual
filaments of cells. Cell
walls contain a hair
material called chitin.
Hyphae digest through
materials to obtain nutrients
• Fungi cannot run, swim, or fly in search
of food -- the mycelium makes up for
the fungus's lack of mobility by its
ability to grow rapidly throughout a
food source.
• more than 100,000 known species of
fungi
• play an important role as decomposers
• recycle nutrients such as nitrogen and
carbon
• Common food sources for fungi are
fallen logs, bodies of dead animals, or
the wastes of living organisms.
• some species of fungi are parasites…
Ringworm
Reproduction of Fungi
• Fungi reproduce by releasing large
numbers of microscopic spores.
• Spores are haploid single cells with
thick cell walls that function as the
dispersal stage in the reproduction
of fungi.
• These tough reproductive cells are
spread by the wind and can
withstand unfavorable conditions for
long periods of time.
• When conditions are favorable
again, they can germinate (start to
grow) and grow into new fungi.
• Asexual
• Most reproduction is by asexual spores
called conidia.
• Sexual
• Hyphae from opposite mating types fuse,
forming a heterokaryotic structure which
then produces dikaryotic hyphae.
• The fruiting body is called an ascocarp. It
is composed of dikaryotic hyphae and
haploid hyphae.
Classification
(by method of reproduction)
Chytrids
• These microscopic fungi live mostly in
water and soil.
• Spores (asexual reproduction) and
gametes (sexual reproduction) have
flagella. These are the ONLY fungi with
flagellated cells.
Types of Fungi
• Zygote Fungi
– mostly terrestrial and live in soil or on
decaying plant and animal material
– reproduces asexually via sporangia or
sexually forming zygosporangium
Types of Fungi
• Sac Fungi
– live in marine, freshwater, and terrestrial habitats.
– They range in size from single-celled species to
large morels.
– get their name from a specialized reproductive
structure or "sac," called an ascus.
– Like the zygote fungi, sac fungi usually reproduce
asexually when conditions are suitable, and
sexually when conditions become harsh.
Ascus (reproductive structure) of
Sac Fungus
Types of Fungi
• Club Fungi
– probably most familiar - mushrooms,
puffballs, and rusts, are classified as club
fungi.
– named for their club-shaped, sporeproducing structure called a basidium.
– Many club fungi are important
decomposers of wood and other plant
material.
– Club fungi primarily reproduce by sexual
reproduction.
Types of Fungi
• Yeasts – A TYPE OF SAC FUNGI
– Single-celled fungi
– liquid or moist habitats including plant sap and
animal tissues
– Yeasts reproduce asexually, by simple cell
division or by small "buds" off a parent cell.
– Some yeast species also reproduce sexually
– Humans have used yeasts to raise bread dough
and ferment alcohol for thousands of years.
YEAST
Types of Fungi
• Molds – A TYPE OF SAC FUNGI
– Any fungus that grows very rapidly on a surface is
generally referred to as a mold.
– asexual reproduction.
– Mold spores are airborne and are found almost
everywhere.
– Warm, moist environments are ideal for spore
germination and mold growth. Even the cellulose in
paper and book covers provide ample nutrition for
certain molds. Molds can also damage clothing, leather,
paint, and even many plastics.
Importance of Fungi
• Symbiotic Fungi
• Symbiosis -- a close relationship between
two different species that benefits at least
one of them.
• Fungi participate in a number of important
mutualistic relationships.
SYMBIOSIS
• Lichens A lichen is a mutualistic pairing of a
fungus and an alga.
– Lichens are important pioneer organisms on
newly cleared rock and soil surfaces
– In the arctic tundra, caribou graze on lichens
at times of the year when other foods are
unavailable.
– As tough as lichens are, however, many do
not tolerate air pollution. -- The death of
sensitive lichens in an area can be an early
warning of poor air quality.
Lichen
Lichens
Lichen
SYMBIOSIS
• Mycorrhizae -- symbiotic relationships with most land
plants.
– fungal hyphae and plant roots.
– The fungi absorb water and essential minerals from
the soil and provide these materials to the plant.
– The fungal mycelium greatly increases the surface
area of the root in contact with the soil, which
increases the plant's absorption of water and
minerals.
– The sugars produced by the plant, in turn, nourish
the fungi.
Harmful Fungi
• Disease-causing Fungi
– Of the 100,000 known species of fungi about 30
percent are parasites, mostly on or in plants.
– Animals are much less susceptible to parasitic fungi
than are plants.
– Only about 50 species of fungus are known to be
parasitic in humans and other animals.
– yeast infections of the lungs, the skin disease called
ringworm, or fungi that attack the feet and cause
intense itching and sometimes blisters = athlete's foot
– Fungicides are substances that kill fungi without
seriously harming the host organism.
Ringworm
Piptoporus portentosus. it will
destroy most of the heart-wood of
the host tree.
• Commercial Uses of Fungi
– edible mushrooms, other edible fungi include
truffles.
– The distinctive flavors of certain kinds of
cheeses come from the fungi used to "ripen"
them.
– As mentioned earlier, yeasts are particularly
important in baking, brewing, and
winemaking. And a number of antibiotics also
come from fungi.
Truffles
Morel
• The Role of Fungi in Chemical Cycling –
– Fungi and bacteria are the principal decomposers
that supply ecosystems with the nutrients essential
for plant growth.