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Fungi
AP Biology
Crosby High School
Absorptive Nutrition
Secretes Hydrolytic Coenzymes
Types of absorption
– Saprobes
– Parasitic
– Mutualistic
Extensive Surface Area and Rapid
Growth
Hyphae: tiny filaments that make fungal
body
– Tubular walls surrounding plasma membrane
– Mycelium: interwoven hyphae
Septa: cross-wall divides Hyphae into cells
Cell walls made of Chitin
Coenocytic: Aseptate
Haustoria: Hyphal tips that penetrate host
tissue
Fungi Reproduction
Can be asexual or sexual
Produce spores that disperse
– Spores need a moist habitat to grow
Puffballs
Most fungi have heterokaryotic stages
– Most nuclei are haploid
– Heterokaryon: Fusion of two Hyphae
Sexual Life Cycle
Heterokaryon
– Two nuclei exist in different parts of mycelium
– Nuclei may mingle and exchange genes
Plasmogamy: Fusion of parental
cytoplasm
Karyogamy: Fusion of haploid nuclei
Dikaryotic: Interim btwn. Plas. and Kary.
Phylum Chytridiomycota
Mainly aquatic
– Saprobes
– Parasitic attack plant, protists and animals
Originally classified under protists
– Absorptive
– Chitin cell walls
Most form Coenocytic Hyphae
Flagella suggest early origin
Phylum Zygomycota
Mostly terrestrial
Mycorrhizae: mutualist w/ plant roots
Coenocytic w/ septa only at reproductive
cells
Rhizopus stolonifer (black bread mold)
– Asexual phase forms bulbs containing spores
– Reproduces sexually if conditions deteriorate
Pilobolus: aims spores
Phylum Ascomycota
Among most devastating plant pathogens
Saprobes of plants
½ are mutualists w/ algae as lichens
Spore production in Asci
Many asexual spores at tips of
Conidiophores
– Naked spores called Conidia
Heterokaryotic Stage
Plasmogamy produces ascogonium
Cells at tips develop into asci
Karyogamy combines parental genomes
and meiosis forms 4 ascospores
Mitosis doubles ascospore number
Phylum Basidiomycota
Basidium: Club Fungus (“Little Pedestal”)
Decomposers of wood
Mushrooms, shelf fungi, puffball, rusts and
smuts
Periodically produce Basidiocarps
Asexual reproduction less common
Mushrooms sprout in a few hours
Other Classifications
Molds: Rapidly growing, asexual fungi
– Refer only to asexual spores early in life
– May become sexual as Zygosporangia, Ascocarp, or
Basidiocarp
– Deuteromycetes (imperfect fungi)
Yeasts: Unicellular fungi in moist env.
– Cellular division or budding
– Some rep. sexually: Ascomycota or Basidiomycota
– Saccharomyces cerevisiae
Other Classifications (cont.)
Yeasts (cont.)
– Rhodotorula: shower curtains
– Candida: present in epithelial tissue
Lichens
– Mutualistic w/ algae
Algae provide food (cyanobacteria fixes Nitrogen)
Fungus provides env. Water, minerals, gas exchange,
protecttion
– Reproduce as asexual symbiont (Soredia)
Mycorrhizae: Mutualistic plant roots and fungi
Ecological Impact
Decompose and recycle elements
Pathogens
– Claviceps purpurea
Forms ergots on rye
Lysergic acid causes Gangrene, nervous spasms, burning
sensations, hallucinations, and temporary insanity
– Mycosis
Ringworms
Candida albicans
Commercial use
– Many types of consumptions
– Penicillin comes from Penicillium
Lichen Structure
Basidiomycota
Basidiomycota Life Cycle
Fairy Ring
Ascomycota Life Cycle
Zygomycota Life Cycle
Fungi Structure