Key Terms
Thallus
Vegetative body of a fungus
Yeast
Unicellular fungus
Hyphae
Thread-like filaments that make up multicellular fungi
Mycelium
Mass of hyphae; the main fungal body
Dimorphic fungi
Can switch between unicellular and multicellular forms depending on environmental conditions
Three methods
1. Fragmentation: hyphae break off and grow into new colonies 2.
Meiosis
Diploid nucleus undergoes meiosis; produces haploid spores
Asexual reproduction
Sporangiospores produced in sporangia. Black tips of bread mold = sporangia packed with spores.
Sexual reproduction
Triggered by unfavorable conditions. Two mating strains (+ and -) produce gametangia that fuse.
Zygospore
Thick-walled dormant structure of Zygomycota; contains diploid nuclei; resistant to harsh conditions
Key reproductive structure
Ascus (plural: asci) - a sac containing haploid ascospores. Asci are housed in a fruiting body called the ascocarp.
Examples
Baker's yeast, truffles, morels, Aspergillus, Penicillium
Includes
Edible mushrooms, shelf fungi, smuts, rusts, Cryptococcus neoformans, death cap (Amanita phalloides)
One exception
Geosiphon pyriformis hosts a cyanobacterium (Nostoc) as an endosymbiont instead of plant roots.
Important members include
Penicillium (cheese ripening, antibiotic source) and Aspergillus (food contaminant, aflatoxin producer).