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EXAMINATION
& EXERCISES #3 FOR THE ASCOMYCOTA (Contact)
_ _ _ _ _ _ _ _
_ _ _ _ _ _ _ _ _ _ _ _ _ _ Fill in all blanks; underscore all correct parenthesized
sections:
(Micheli) (de Bary)
(Strasburger) (Harper) (Raper)
(Thaxter) about (1850)
(1875) (1900) (1925). The unused cytoplasm
left in an ascus after spore delimitation is called _________. 2. Eremothecium
ashbyii is an important fungus {because it is an important plant
pathogen) (because it is an important
vitamin source) (because of its scavenger activity in soil) (because it
produces an important antibiotic.) 3. Three species of Taphrina are: T.
________, parasitic on __________; T. ____________, parasitic on ____________; T.
__________________, parasitic on _________________. 4. (All yeasts) (Not all yeasts) are in the Ascomycota. 5. Endomyces reproduces
vegetatively by (sporangiospores)
(arthrospores) (blastospores) (ascospores.) 6. Vegetative cells of Taphrina are typically
(uninucleate) (binucleate) (multinucleate). Chlamydospores--ie. Ascus initials-- in T.
deformans are formed (subcuticularly)
(just under the epidermis) (scattered
among the host cells near the surface
of the attacked host organ). 7. All fungi assigned to the Hemiascomycetes (produce many-spores
asci) (lack ascoearps) (are diploid
or dicaryotic in their
vegetative phase). Representative genera of the
Hemiascomycetes __________, __________ and __________. 8. Dipodascus belongs
in the order ____________. Asci of Dipodascus
have (four) (eight) (many)
ascospores. 9. Arachniotus is a
member of the family, in the order __________________.. 10. An Oidium p'f imperfect
stage is characteristic of (Elsinoe)
(Uncinula) (Thielavia) (Myriangium) (Phyllactinia) (Arachniotus) (Sphaerotheca). 11. Members of the genus
incite plant diseases known as "spot anthracnoses." These diseases are most prevalent
in (the tropics)
(the temperate zones). 12. In culture, on agar,
species of Taphrina may closely resemble (Arachniotus) (Saccharomyces) (Endomyces) (Schizosaccharomyces) (Ashbya) -- both macroscopically
and microscopically. 13. In comparing
Arachniotus trisporus and Aspergillus amstelodami, it is
found that: ~(both produce catenu~e conidia) (the conidia of both
are colored) (the conidia of neither are colored) (thet~asci are very different) ~(in both, the asci have a
scattered arrangement) (in both,
the ascocarp has a firm and well-defined peridium) (both produce chlamydospores)
(both produce racquet mycelium) (their natural habitats are similar.) 14.
"Aspergillosis" in birds usually involves infection by (Aspergillus
niger) (Aspergillus flavus) {Aspergillus fumigatus). 15.
The following species of Penicillium incite important fruit
rots: P. _____________, P _______________, and
P. ________________ 16.
Asci arise from ascogenous hyphae in (Erysiphe) (Arachniotus) (Endomycopsis) (Dipodascus) (Eurotium). 17.
"Proasci" are encountered in the genus _______________. 18.
In nature, yeasts may be found (on the surface of ripe fruits) (in the soil) (on leaf surfaces) (in
the atmosphere). 19.
A yeast (might) (would not) be expected to grow on a medium that was too acid to allow development
of most bacteria but on which a wide variety of filamentous
fungi could thrive. 20.
Saccharomyces cerevisiae (can)
(cannot) utilize starch as a carbon source. 21.
In "haplobiontic" yeasts, cell fusion occurs immediately
preceding ascus formation. An example of a haplobiontic yeast would be (Schizosaccharomyces octosporus) (Saccharomyces cerevisiae). 22.
The yeast ordinarily used in baking
(is) (is not) a "sporogenous" yeast. The metabolic
produce of the yeast that is concerned in the leavening of
dough is ___________________. 23.
To induce rapid multiplication of cells of Saccharomyces in
a suitable medium, the culture should be (well aerated) (kept under conditions of low aeration). 24.
In the presence of an abundance of free oxygen Saccharomyces
cerevisiae tends to produce _______________ and ________________as end-products of its
respiration. When the oxygen supply is low, alcohol and ____________are produced. The
alcohol is (ethyl alcohol) (methyl
alcohol) (butyl alcohol). 25.
Many species of Taphrina produce "secondary"
ascospores in their asci, with the result that there are large numbers of spores in the spore sacs. This (is)
(Is not) the way Taphrina defommans behaves. 26.
In the space provided, indicate the order to which you would
assign each of the following genera:
27. Classify the following
as indicated:
28. The Ascomycota genus Taphrina
is assigned to the "Hemiascomycetes" (because it forms no conidia)
(because some species produce
multi-spored asci) (because no
ascocarps are produced) (because all
fungi that produce budding
yeast-like cells are assigned to this sub-class). 29. The value of a given
unit on a stage micrometer scale is absolute-- always fixed. On the other
hand, a given unit on an ocular micro-
meter scale varies in value with the lens combination employed. Does the
value increase or decrease when
you change from a low power objective to an objective of higher
magnification? 20. For each of the items
in the left column select from the column at the right one fungus or fungal
group that fits that item, and enter
the number of the selected organism or group in the appropriate blank:
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