Ascomycota
\n| Ascomycota |
|---|
\n |
|---|
\n| \n\n |
| Classeses |
|---|
\n\nArchaeascomycetes
\nHemiascomycetes
\nEuascomycetes\n |
\n
Members of the
Division Ascomycota are known as the
Sac Fungi and are
fungi that produce
spores in a distinctive type of microscopic
sporangium called an
ascus (Greek for a "bag" or "wineskin"). This
monophyletic grouping was formerly known as the
Ascomycetae and is an extremely significant and successful group of organisms (12,000 species in 1950), accounting for some 75% of all described fungi. Included are most of the fungi that combine with
algae to form
lichens. The majority of fungi that lack morphological evidence of sexual reproduction are placed here. Better known examples of sac fungi are
yeasts, morels, truffles, and
Penicillium.
An ascomycete produces great numbers of
asci at any one time, and these may be contained in a structure called an
ascocarp. Each ascus contains eight (or a multiple of 8)
ascospores, the result of one round of
mitosis following
meiosis. The resulting haploid nuclei are surrounded by membranes (from the plasma membrane in Euascomycetes; from the nuclear membrane in Hemiascomycetes) and eventually a spore wall.
An exception to the structure described above are the
yeasts, which are secondarily unicellular.
External links
\n* Tree of Life Web Project: Ascomycota
\n
