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asci with ascospores x400.
x40. A cup fungus sexual structure growing on the bark of a dead tree.
x100. This ascus bearing structure is shown on a cross section of a
crab apple leaf.
(baker's yeast) x1000. These are single
celled ascomycetes that often reproduce asexually by budding. This can
be seen in some of the yeast cells near the center of the illustration.
basidia with basidiospores x1000. This is
the gill of a mushroom. Two basidia are shown, each with 4
basidiospores attached externally by little stalks.
(wheat rust) aecia and pycnia x40. This is
a cross section of a barberry leaf showing two stages of this fungus's
complex life cycle. Aeciospores are on the upper surface and
pycniospores on the lower surface. Pycniospores will infect wheat
uredia x40. The illustration shows a wheat
stem with the bases of two leaves wraped around it. The leaves have
groups of uredospores on their surfaces. These spores can blow around
and infect other wheat plants.
uredospores on wheat leaves x100. The red
color of these spores is the basis of the name "wheat rust".
teliospores x100. These two celled wheat
rust spores form at the end of the growing season. They fall to the
ground and overwinter there. In the spring the spores germinate on the
ground, produce a basidium, and the resulting basidiospores infect
maydis (corn smut)
x40. Part of a greatly distorted corn seed that is infected. The red
areas are clusters of fungal spores.
maydis spores inside corn.
(bread mold) hyphae x100. Unlike the
ascomycetes and basidiomycetes, the hyphae of the zygomycetes is
coenocytic. That means that there are few or no partitions dividing the
hyphae into individual cells.
asexual sporangium x100. You can see
several coenocytic hyphae, one of which ends in a sporangium.
asexual spores in sporangium x400. Several
nuclei crowd into the end of a hypha. A septum forms (one of the few in
the otherwise coenocytic hyphae) forming a sporangium and separating
these nuclei from the rest of the hypha. Each nucleus then becomes a
haploid asexual spore.
zygospore x100. This diploid (2N) spore is
fromed from the fusion of two nuclei, one each from two sexually
compatible hyphae. Look carefully inside the spore and you can see the
diploid nucleus. This spore, with its thick coat, can survive draught
cold and lack of food. When conditions improve the spore germinates,
meiosis occurs and the spore grows an asexual sporangium full of
x400 showing the swolen end of the hypha that bears chains of
x1000. The distinctive finger-like chains of conidiospores are shown.
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