Body Structure

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Body Structure

• The morphology of multicellular fungi
• Enhances ability to absorb nutrients
• Chitin

Hyphae
Mycellum
Figure 31.2
2
Hyphal Structure

• Most are multicellular
• Cells divided by septa
• Some have no cross wall- Coenocytic

Figure 31.3
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Hyphal Structure
haustoria
Figure 31.4a, b
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Hyphal Structure
Figure 31.4a, b
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Mycorrhizae

• Are mutually beneficial relationships between
  fungi and plant roots
• Mycorrhizae fungus roots
• Delivers minerals and receives organic nutrients
• Ectomycorrhizal fungi Grow in extracellular
  spaces of roots
• Endomycorrhizal fungi Hyphae go through cell
  wall to plasmamembrane

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Fungus-Plant Symbiosis

• Mycorrhizae
• Increase plant productivity

RESULTS
RESULTS
Figure 31.21
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Malted barley
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Saccharomyces cerevisiae
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• Brewer's yeast tolerate up to about 5 alcohol.
  Beyond this alcohol level the yeast cannot
  continue fermentation. Wine yeast on the other
  hand tolerates up to about 12 alcohol. The level
  of alcohol tolerance by yeast varies from 5 to
  about 21 depending on yeast strain.
• Part 1 Aerobic (Oxygen is present) This is the
  initial rapid process where the yeast is doubling
  its colony size every 4 hours. (Usually 24-48
  hours)
• Part 2 Anaerobic. (No oxygen present) Slower
  activity and the yeast focuses on converting
  sugar to alcohol rather that increasing the
  number of yeast cells. (This process can take
  from days to weeks depending on the yeast and the
  recipe)

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• The overall process of fermentation is to convert
  glucose sugar (C6H12O6) to alcohol (CH3CH2OH) and
  carbon dioxide gas (CO2). The reactions within
  the yeast to make this happen are very complex
  but the overall process is as follows
• C6H12O6    gt   2(CH3CH2OH)             
  2(CO2)    Sugar      gt      
  Alcohol                Carbon dioxide gas
  (Glucose)               (Ethyl alcohol)
•  Note The sugars used can be a range of
  fermentable sugars. These sugars are converted by
  enzymes to glucose which is then convered to
  alcohol and CO2

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Diploid phase follows karyogamy

• Short-lived (2n) spore-producing structures and
  (1n) spores

Ascocarp
Basidiocarp
Sporangia
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• Concept 31.3 Fungi descended from an aquatic,
  single-celled, flagellated protist
• Fungi and Animalia as sister kingdoms
• Fungi early colonizers of land, probably as
  symbionts with plants.

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• Concept 31.4 Fungi radiated into a diverse set
  of lineages

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Chytrids

• Found in freshwater and terrestrial habitats
• They can be saprobic or parasitic
• Zoospores unique with flagellated spores

Hyphae
Figure 31.10
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Zygomycetes

• Fast growing bread and fruit molds
• Can also be parasitic or symbiotic relationship

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Zygomycetes
Key
Haploid (n)
Heterokaryotic (n n)
Diploid (2n)
PLASMOGAMY
Rhizopus growing on bread
Mating type ()
Mating type ()
100 µm
SEXUAL REPRODUCTION
Dispersal and germination
Zygosporangium (heterokaryotic)
Sporangia
KARYOGAMY
Diploid nuclei
Sporangium
ASEXUAL REPRODUCTION
Zygospore
MEIOSIS
Dispersal and germination
Figure 31.13
Mycelium
50 µm
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Zygomycetes

• Pilobolus aim their sporangia toward the light

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related http//www.youtube.com/watch?vTrKJAojmB1
Y
Figure 31.14
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Zygomycetes

• Pilobolus aim their sporangia toward the light

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Glomeromycetes

• arbuscular mycorrhizae
• See Figure 31.15

http//www.agro-genesis.com/pics/cropscience_rhizo
gold1.jpg
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Ascomycetes
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Glomeromycetes

• Spores produced in a saclike asci sac fungi
• Asci are within the ascocarp

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Basidiomycetes

• Include mushrooms and shelf fungi
• Clublike structure
  called a basidium

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Mushrooms are examples of basidiocarps
Figure 31.20
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• Concept 31.5 Fungi have a powerful impact on
  ecosystems and human welfare

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Decomposers

• Essential recycling between the living and
  nonliving world

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Fungus-Animal Symbiosis

• Helping break down plant material

Figure 31.22
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Lichens

• Symbiotic association of photosynthetic
  microorganisms held in fungal hyphae

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Lichens

• The fungal component
• Is most often an Ascomycete
• Algae or cyanobacteria
• Occupy an inner layer
  below the lichen
  surface

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Pathogens

• About 30 of known fungal species
• Are parasites, mostly on or in plants

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Practical Uses of Fungi

• Make cheeses, alcoholic beverages, and bread
• Genetic research on fungi is leading to
  applications in biotechnology
• Antibiotics produced by fungi treat bacterial
  infections

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Charophytes
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Overview The Greening of Earth

• 3 billion years terrestrial surface was lifeless
• Now roughly 290,000
  living plant species