Chapter 21: Fungi

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Chapter 21 Fungi

• Biology- Kirby

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21-1 The Kingdom Fungi

• Fungi are eukaryotic heterotrophs that have cell
  walls.
• These cell walls are made of chitin.
• Fungi digest food outside their bodies and then
  absorb the nutrients.
• Some fungi absorb nutrients from decaying matter,
  while others are parasites that absorb nutrients
  from their hosts body.

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21-1 The Kingdom Fungi

• Structure Function of Fungi
• Multicellular fungi are composed of thin
  filaments called hyphae. Each hypha is one cell
  thick, has many nuclei, and sometimes interior
  walls.
• When many hyphae are tangled togather, they form
  a thick mass called a mycelium.

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21-1 The Kingdom Fungi

• The mushroom you see is the fruiting body
  (reproductive structure growing from the mycelium
  in the soil) of the fungus.
• Fairy Rings- Clusters of mushrooms are often part
  of the same mycelium. As time passes, the
  mushrooms will only grow on the edge of the
  mycelium producing a ring of mushrooms.

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21-1 The Kingdom Fungi

• Reproduction in Fungi
• Asexual-
• 1. hyphae break off and grow independently.
• 2. produce spores that spread their genes.
• Sexual-
• The gametes are the same size, so they are
  referred to as a and -. The and meet and
  fuse together producing a diploid zygote.

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21-1 The Kingdom Fungi

• How Fungi spread
• Fungi produce dry lightweight spores that scatter
  easily.
• Many spores are often spread by other organisms
  which carry them.
• These spores need the right temperature,
  moisture, and food to survive.

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21-2 Classification of Fungi

• Fungi are classified according to their structure
  and reproduction method.
• There are 4 main groups of fungi
• Common mold Zygomycota
• Sac fungi Ascomycota
• Club fungi Basidiomycota
• Imperfect fungi Deuteromycota

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21-2 Classification of Fungi

• Common Molds
• Grows on meat, cheese, and bread.
• Sexual reproduction
• 2 kinds of hyphae
• Rhizoids- rootlike hyphae that penetrate the
  breads surface.
• Stolons- stemlike hyphae that run along the
  surface of the bread.

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21-2 Classification of Fungi

• Sac fungi
• Have a cuplike shape.
• Asexual sexual reproduction.
• Ascus- reproductive structure within the fruiting
  body.
• Yeasts- unicellular fungi-
• Budding- asexual process of dividing yeast cells.

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21-2 Classification of Fungi

• Club fungi
• Have a reproductive structure called the basidium
  that looks like a club.
• Most complex life cycle of the fungi.
• Very diverse group of fungi.
• Imperfect fungi
• Fungi that do not have a sexual phase of their
  life cycle.

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21-3 Ecology of Fungi

• In order for fungi to get food, their mycelia can
  grow very rapidly into tissues and cells of other
  organisms.
• Fungi help maintain equilibrium in ecosystems
  because they break down bodies and wastes of
  other organisms and recycle the nutrients.
• Most secrete an enzyme to break down matter.

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21-3 Ecology of Fungi

• Parasitic fungi cause plant, animal, and human
  diseases.
• Some fungi form symbiotic relationships where
  they both benefit (mutualism).
• Example- Lichens- relationship between a fungus
  and a photosynthetic organism. Mycorrhizae-
  relationship between a fungus and a plant.