Kingdom Fungi
Finding the Fungus Among Us
Characteristics of Fungi
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Eukaryotic
Most are Multicellular
Filamentous body plan
Heterotrophic by Absorption
Produce spores by sexual and asexual
reproduction
• Haploid for part or most of life cycle
• Cell wall made of chitin
• No movement: change location by
growth of body or dispersion of spores
Body Plan of Fungi
• Mycelium = network of filaments
• Hypha = individual filament
(plural = hyphae)
• Septum = partition dividing cells,
has pore for distribution of
nutrients
• Reproductive structure extends
from main body, produces
spores
The Filamentous Body of a Fungus
(a) Mycelium
(c) Hyphal Cells (cutaway)
Cytoplasm
(b) Individual Hyphae
Haploid
Nuclei
Septum
Pore
Cell Walls
Fungal Nutrition
• Heterotropic by absorption
– secrete digestive enzymes
– digest macromolecules outside the body
– absorb digested nutrients
• Three types of interactions
– Saprophytic = digestion of dead organisms,
act as decomposers
– Parasitic = digestion of live organisms,
causing disease
– Mutualistic = beneficial relationship for two
independent organisms
Saprophytes
Fungus on a pinecone
Soil Fungus
Woodrot
Parasites
Corn Smut
Athlete’s Foot Fungus
Ringworm
Candida
Ergot
Lichen: Mutualism Between Alga and Fungus
Algal Layer
Fungal Hyphae
Attachment
Structure
Mycorrhizae: Mutualism Between
Fungus and Plant Roots
Mutualism between
Leaf Cutter Ants and Fungus
Leaf Cutter Ant
Fungus “Garden”
Ants bring leaves to nest
Fungus digests leaves and absorbs nutrients
Ants “harvest” ends of fungal hyphae
Applying Your Knowledge
1. Parasitic
2. Saprophytic
3. Mutualistic
Which mode of nutrition
A. Provides a benefit for the fungus and its
symbiotic partner?
B. Is shown by athlete’s foot fungus?
C. Involves digestion of dead organisms?
Sexual Reproduction
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Hypha from mycelia of
opposite mating types fuse
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Fusion of two haploid nuclei
forms diploid zygote
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Zygote produces haploid
spores by meiosis
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Each spore germinates to
produce a haploid mycelium
Chytrid Fungi
• Flagellated, swimming spores require water for
dispersal
• All fungi descended from a flagellated ancestor
shared with animals, only this group retained
flagella
Zygote Fungi
• Live in soil and on decaying plant matter
• Zygosporangia = reproductive structures
producing haploid spores
Sac Fungi
• Ascus = sac that surrounds haploid
ascospores
Cup Fungus
Morrels
Truffles
Club Fungi
• Basidium = club-shaped reproductive
structure that produces basidiospores
Puffball
Shelf Fungus
Mushrooms
Imperfect Fungi
• Sexual reproduction has not been
observed
Staurospore
Penicillium on apple
Beneficial Effects of Fungi
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Act as decomposers in ecosystems
Can break down pollutants
Produce antibiotics
Assist in plant growth
Pioneer species allowing
colonization of soil-poor areas
• Provide food for other organisms
Applying Your Knowledge
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Chytrids
Zygote Fungi
Sac Fungi
Club Fungi
Imperfect Fungi
Which group of fungi
A. Encloses haploid spores within an ascus?
B. Has flagellated spores?
C. Has an umbrella-shaped reproductive
structure called a basidium?
D. Has not shown sexual reproduction?
Applying Your Knowledge
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Chytrids
Zygote Fungi
Sac Fungi
Club Fungi
Imperfect Fungi
Which group of fungi
A. Are found on as a topping your
mushroom pizza?
B. Caused the pizza dough to rise?
C. Make up the fuzzy structure on the twoweek old loaf of bread in your cupboard?
Applying Your Knowledge
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Prokaryotes
Protists
Fungi
Plantae
Animalia
Which kingdom/domain
A. Has organisms that are heterotrophic by
ingestion?
B. Has cell walls made of chitin?
C. Reproduces by binary fission?