L32 (Fungi) Key Terms

yeast

single-celled fungus. yeasts produce asexually by binary fission or by the pinching of small buds of a parent cell, many fungal species can grow both as yeasts and as a network of filaments; relatively few species grow only as yeasts

hyphae

one of many connected filaments that collectively make up the mycelium of a fungus

chitin

a structural polysaccharide, consisting of amino sugar monomers, found in many fungal cell walls and in the exoskeletons of all arthropods

septa

one of the cross-walls that divide a fungal hyphae into cells, generally have pores large enough to allow ribosomes, mitochondria, and even nuclei to flow from cell to cell

mycelium

the densely branched network of hyphae in a fungus

arbuscules

specialized branching hyphae that are found in some mutualistic fungi and exchange nutrients with living plant cells

mycorrhizae

a mutualistic association of plant roots and fungus

arbuscular mychorrhizal fungi

a symbiotic fungus whose hyphae grow through the cell wall of plant roots and extend into the root cell (enclosed in tubes formed by invagination of the root cell plasma membrane)

spores

in fungi, a haploid cell, produced either sexually or asexually, that produces a mycelium after germination

ectomycorrhizal fungi

a symbiotic fungus that forms sheaths of hyphae over the surface of plant roots and also grows into extracellular spaces of the root cortex

plasmogamy

in fungi, the fusion of the cytoplasm of cells from two individuals; occurs as one stage of sexual reproduction, followed later by karyogamy

karyogamy

in fungi, the fusion of haploid nuclei contributed by the two parents; occurs as one stage of sexual reproduction, preceded by plasmogamy

dikaryotic

referring to a fungal mycelium with two haploid nuclei per cell, one from each parent

deuteromycetes

traditional classification for a fungus with no known sexual stage

molds

informal term for a fungus that grows as a filamentous fungus, producing haploid spores by mitosis and forming a visible mycelium

chytrids

a member of the fungal phylum Chyrtridiomycota, mostly aquatic fungi with flagellated zoospores that represent an early-diverging fungal lineage

zoospores

flagellated spore found in chytrid fungi and some protists

mucuromycota (mucuromycetes)

include fungi that form arbuscular mycrorrhizae with plants

zygomycota (zygomycetes/zoopagomycetes)

multicellular parasites or commensal symbionts of animals; sexual reproduction, where known, involves the formation of a sturdy structure called a zygosporangium

zygosporangium

In zygomycete/zoopagomycete fungi, a sturdy multinucleate structure in which karyogamy and meiosis occur

ascomyectes

a member of the funal phylum Ascomycota, commonly called sac fungus, the name comes from the saclike structure in which the spores develop

microsporidians

a member of the fungal phylum Microsporidia, unicellular parasites of protists and animals; microsporidians and their sister taxon (cryptomycetes) are a basal fungal lineage

asci

sacs found in the fungal phylm Ascomycota where sexual spores (ascospores) are formed and stored

conidia

a haploid spore produced at the tip of a specialized hypha in ascomycetes during asexual reproduction

basidiomycetes

a member of the fungal phylum Basidiomycota, commonly called club fungus (name comes from the club-like shape of the basidium)

basidium

a reproductive appendage that produces sexual spores on the gills of mushrooms (club fungi)

basidiocarps

elaborate fruiting body of a dikaryotic mycelium of a club fungus

endophytes

a harmless fungus, or occasionally another organism, that lives between cells of a plant part or multicellular alga

lichen

the mutualistic association between a fungus and a photosynthetic alga or cyanobacterium

mycosis

fungal infection