Chapter 22 Fungi

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Transcript Chapter 22 Fungi

Chapter 22 Fungi
INTRODUCTION 22-1
Fungi
Some of the most unusual
and peculiar organisms on
earth are members of the
Kingdom Fungi.
 I. Fungi are Classified In their own Kingdom
 A.
Fungi are Eukaryotic and mostly
multicellular organisms (yeast are
unicellular).
1. Fungi were first classified with plants
because they were immobile and appear
“rooted” in the soil.
 B. Differences between fungi and plants
 1. Fungi are heterotrophic. They do not contain chlorophyll
and obtain their energy by absorbing organic molecules from
their surroundings
 2. Fungi have filamentous bodies. Plants have a variety of cell
and tissue types. Fungi are made of long slender filaments
woven tightly together to form the fungus reproductive
structures.
 3. Fungal cell walls contain chitin. Chitin is found in
the exoskeleton of insects and arthropods. Plant cell
walls are made of cellulose.
 4. Fungi have nuclear mitosis. The nuclear
envelope disappears in mitosis of plants-mitosis
takes place in the nuclear envelope. The nuclear
envelope remains during mitosis in fungi. Mitosis
takes place in the nuclear envelope rather than the
cell.
 C. Fungi are well suited for Absorbing nutrients.
 1. The part of fungi we actually see is the reproductive
structure of the fungus. The hypha lies woven within the
tissues or underground.
 2. Bodies (except yeast) are made of filaments called hyphae.
Hyphae tangle together and make a mass called mycelium.
 3. Each of the Hyphae are divided into a long string of cells by
septa – partial dividers that let cytoplasm flow freely from cell
to cell- many have several nuclei.
 D. Obtaining Food
 1. All fungi digest food outside their bodies.
 2. they secrete powerful digestive enzymes that break down
organic matter into small molecules.
 3. These molecules are then absorbed by the fungus and used
as energy.
 4. Nonliving organic matter – leaves, branches, animal
corpses, and waste materials
 5. Living hosts – Which they weaken and often infect with
disease (plants and animals)
 6. fungi often attack materials humans consider inedible –
paper, cardboard, cloth, paint, leather, waxes, fuel, and
petroleum.
 E. Commercial benefits
 1. Yeast – produce CO2 and ethanol. They are used in baking,
brewing, and wine making.
 2. Cheese – blue cheese, etc. Making of foods
 3. Antibiotics – penicillin and cyclosporine ( used to suppress
the immune system during organ transplants.