• Contractile vacuole action
• Amoeboid movement
• See it!
• Chapter 31 ~
Fungi
Humongous Fungus
Honey Mushroom Blankets Forest,
Kills Trees
It is as large as
1,665 football fields
combined. It is 3.4
square miles in size and
covers 2,200 acres of
land in the Blue
Mountains of eastern
Oregon.
Fungi
• Heterotrophic by absorption
(exoenzymes)
• Decomposers (saprobes),
parasites, mutualistic
symbionts (lichens)
• Hyphae: body filaments
•septate (cross walls)
•coenocytic (no cross walls)
• Mycelium: network of hyphae
• Chitin cell walls
(polysaccharide)
Cell wall
Nuclei
Cell wall
Pore
Septum
Septate hypha
Nuclei
Coenocytic hyph
LE 31-2
Reproductive structure
Hyphae
Spore-producing
structures
20 µm
Mycelium
Fungus Life Cycle
Most have 3 distinct phases:
1.
Haploid (n)
2.
Heterokaryotic (n + n)
(think of Sordaria)
3.
Diploid (2n)
Asexual phases: (n spores, n clones)
Sexual Phases: (n spores, w/ genetic
variety)
Plasmogamy (cytoplamic fusion)
Dikaryotic (n + n)
Karyogamy (nuclei fusion)
Diploid (2n)
Meiosis (spores n)
Bread Mold Life cycle
Key
Heterokaryotic
stage
Haploid (n)
Heterokaryotic
(n + n))
PLASMOGAMY
(fusion of cytoplasm)
Diploid (2n)
KARYOGAMY
(fusion of nuclei)
Spore-producing
structures
Zygote
Spores
ASEXUAL
REPRODUCTION
Mycelium
SEXUAL
REPRODUCTION
MEIOSIS
GERMINATION
GERMINATION
Spore-producing
structures
Spores
Fungi Diversity, I
• Phy: Chytridiomycota
•aquatic fungi; chytrids
•lineage closest to protists
(flagella)
• Phy: Zygomycota
•Rhizopus (food mold)
•mycorrhizae: mutualistic
with plant roots
•zygosporangia: resistant
structure (freezing and
drying)
Fungi Diversity, II
• Phy.: Ascomycota
•sac fungi
• yeasts, truffles, morels,
Sordaria
•asci: sexual spores
•conidia: asexual spores
• Phy.: Basidiomycota
• club fungus
•mushrooms, puffballs,
shelf fungus, rusts
•basidiocarps: produce
sexual spores
Specialized Lifestyles, I
• Molds
•only the asexual stage
(asexual spores)
•Penicillium (antibiotic,
cheese)
• Yeasts
•unicellular, asexual
budding
•Saccharomyces (bread,
alcohol)
Specialized Lifestyles, II
• Lichens
• symbiotic association held in a
hyphae mesh
•alga provides food, fungus
provides physical environment
•pioneer organisms
•air pollution detection
• Mycorrhizae
•root and fungi mutualism
•found in 95% of vascular plants
•exchange of organic minerals
•increases absorptive surface of
roots