Transcript Chapter 26 Fungi Table of Contents Section 1 Overview of Fungi Section 2 Classification of Fungi Section 3 Fungi and Humans.

Chapter 26
Fungi
Table of Contents
Section 1 Overview of Fungi
Section 2 Classification of Fungi
Section 3 Fungi and Humans
Chapter 26
Section 1 Overview of Fungi
Objectives
• List the characteristics of fungi.
• Describe how fungi obtain nutrients.
• Distinguish between hyphae and a mycelium.
• Compare the ways fungi reproduce.
• Describe one hypothesis about the origin of fungi.
Chapter 26
Section 1 Overview of Fungi
Characteristics
• Fungi are eukaryotic, nonphotosynthetic organisms
that can be unicellular or multicellular in form.
Chapter 26
Section 1 Overview of Fungi
Characteristics, continued
Obtaining Nutrients
– Fungi are among the most important decomposers
of organic matter.
– Fungi obtain nutrients by secreting enzymes and
absorbing simple organic molecules from their
environment.
Chapter 26
Section 1 Overview of Fungi
Characteristics, continued
Structure of Fungi
– Fungi are made up of short filaments called
hyphae.
• Mats of hyphae are called mycelium.
• Some species have partitions called septa in
their hyphae, making individual cells.
– Fungal cell walls contain chitin rather than
cellulose, which is found in plant cell walls.
Chapter 26
Section 1 Overview of Fungi
Characteristics of Fungi
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Visual Concept
Chapter 26
Hyphae in Fungi
Section 1 Overview of Fungi
Chapter 26
Section 1 Overview of Fungi
Body Structure of Fungi
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Visual Concept
Chapter 26
Section 1 Overview of Fungi
Reproduction
• Most fungi reproduce both asexually and sexually.
Chapter 26
Section 1 Overview of Fungi
Reproduction, continued
Asexual Reproduction
– Asexually, fungi produce thousands of genetically
identical haploid spores, usually on modified cells
of the hyphae.
– When these spores are placed in favorable
environmental conditions, they germinate and
grow new hyphae, each of which can form a
mycelium and produce thousands of new asexual
spores.
Chapter 26
Section 1 Overview of Fungi
Reproduction, continued
Sexual Reproduction
– Fungi occur in mating types that are sometimes
called minus and plus.
– When two different mating types of the same
species encounter one another, the hyphae of one
mating type fuse with the hyphae of the opposite
mating type.
– These fused hyphae give rise to a specialized
structure, which produces and scatters genetically
diverse spores.
Chapter 26
Section 1 Overview of Fungi
Sexual Reproduction
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Visual Concept
Chapter 26
Section 1 Overview of Fungi
Evolution
• Fungi evolved about 460 million years ago.
• Fungi probably evolved from endosymbiotic
prokaryotes and then adapted to various terrestrial
environments.
Chapter 26
Section 2 Classification of Fungi
Objectives
• List characteristics that distinguish three phyla of
fungi.
• Compare the life cycles of zygomycetes,
basidiomycetes, and ascomycetes.
• Distinguish between mycorrhizae and lichens.
• Explain the importance of mycorrhizae and lichens to
the environment.
Chapter 26
Section 2 Classification of Fungi
Types of Fungi
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Visual Concept
Chapter 26
Section 2 Classification of Fungi
Phylum Zygomycota
• The phylum Zygomycota is coenocytic (their hyphae
lack septa).
• Asexual sporangiospores form within sacs called
sporangia.
• Sexual reproduction results in zygospores.
Chapter 26
Section 2 Classification of Fungi
Life Cycle of Zygomycetes
Chapter 26
Section 2 Classification of Fungi
Asexual Reproduction in Zygomycetes
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Visual Concept
Chapter 26
Section 2 Classification of Fungi
Sexual Reproduction in Zygomycetes
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Visual Concept
Chapter 26
Section 2 Classification of Fungi
Phylum Basidiomycota
• The phylum Basidiomycota includes mushrooms.
• Mushrooms are spore-bearing, aboveground sexual
reproductive structures called basidiocarps.
• Basidiocarps produce small, clublike reproductive
structures called basidia, on which basidiospores
form.
Chapter 26
Structure of a
Mushroom
Section 2 Classification of Fungi
Chapter 26
Section 2 Classification of Fungi
Parts of a Mushroom
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Visual Concept
Chapter 26
Section 2 Classification of Fungi
Life Cycle of Basidiomycetes
Chapter 26
Section 2 Classification of Fungi
Sexual Reproduction in Basidiomycetes
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Visual Concept
Chapter 26
Section 2 Classification of Fungi
Phylum Ascomycota
• Most fungi are in the phylum Ascomycota, or sac
fungi.
• Hyphae form a cup-shaped ascocarp, in which
ascospores form.
• Yeast are unicellular Ascomycota and they reproduce
asexually by budding.
– Yeast are used in brewing, baking, and genetic
engineering.
Chapter 26
Section 2 Classification of Fungi
Life Cycle of Ascomycetes
Chapter 26
Section 2 Classification of Fungi
Penicilliium Mold
Chapter 26
Section 2 Classification of Fungi
Asexual Reproduction in Ascomycetes
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Visual Concept
Chapter 26
Section 2 Classification of Fungi
Sexual Reproduction in Ascomycetes
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Visual Concept
Chapter 26
Section 2 Classification of Fungi
Phylum Ascomycota, continued
Deuteromycota
– Fungi that do not have a sexual stage are
classified in a group called fungi imperfecti, or
deuteromycota.
Chapter 26
Section 2 Classification of Fungi
Mycorrhizae and Lichens
• Mycorrhizae are symbiotic structures that form
between plant roots and a fungus.
• The fungus provides certain ions and other nutrients
to the plant and, in turn, the fungus gets sugars from
the plant.
Chapter 26
Section 2 Classification of Fungi
Mycorrhizae and Lichens, continued
• Lichens represent symbiotic relationships between
fungi and photosynthetic organisms, such as
cyanobacteria or green algae.
Chapter 26
Section 3 Fungi and Humans
Objectives
• Describe three ways that fungi cause disease in
humans.
• List three ways that fungi contribute to good health.
• Provide examples of fungi’s industrial importance.
• List three types of food that fungi provide.
Chapter 26
Section 3 Fungi and Humans
Human Fungal Diseases
• Fungi can cause disease in humans when humans
inhale airborne spores, when they eat food
contaminated by toxic fungi, when toxic fungi come in
contact with skin, or when they accidentally eat
poisonous mushrooms.
Chapter 26
Section 3 Fungi and Humans
Human Fungal Diseases
Common Fungal Infections
– Examples of common fungal infections include
ringworm, athlete’s foot, and yeast infection.
Chapter 26
Section 3 Fungi and Humans
Human Fungal Diseases, continued
Other Fungal Illnesses
• Pathogenic fungi that cause serious disease include
Histoplasma capsulatum, Blastomyces dermatitidis,
and Coccidioides immitis.
• H. capsulatum is associated with bird feces.
Chapter 26
Section 3 Fungi and Humans
Fungi in Industry
• Various fungi are used in the production of vitamin B2,
cortisone, penicillin and other antibiotics, and some
genetically engineered drugs.
Chapter 26
Section 3 Fungi and Humans
Fungi in Industry, continued
Fungi and Food Industries
– Fungi are used in the production of familiar foods
such as cheeses, bread, beer, wines, and soy
products.