EXAMINATION & EXERCISES #4
For The AMOEBOZOA, ZYGOMYCOTA, ASCOMYCOTA & BASIDIOMYCOTA
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Fill in the blanks and answer questions
briefly in the spaces provided.
1. Racquet mycelium and cleistothecia with poorly defined or rudimentary peridia are encountered in the family of the
order __________________. The Deuteromycetous forms known as Dermatophytes are believed to be closely
related to this Ascomycetous family because _________________________________, The Dermatophytes are
of interest and importance because ______________________.,
Distinguish between "periplasm" and "epiplasm".
Describe the imperfect stage of a typical powdery mildew.
4. What are "Sooty Molds" and in what geographical area do these predominate? Give an example of a sooty mold.
5. For each of the items in the column at the left select from the column at the right the one fungus or fungal group which best fits that item, and enter the number of the selected organism or group in the appropriate blank:
6. Specialists have long been impressed by the basic similarities between Taphrina and certain members or the
Basidiomycota. What kind of basidiomycete, in particular, does Taphrina resemble? Specify what some of the
points of similarity are.
Discuss the nature, occurrence, and mode of action of spermatia
in the fungi.
8. The majority of the species assigned to the Heterobasidiomycetes are plant pathogens. whereas very few of the
Homobasidiomycetes are known to incite plant disease. List other points or contrast between these two sub-
Classes of the Basidiomycota.
9. State how one would proceed to cross an albino "A" strain with a conidial "B" strain of Neurospora sitiphila if, at
the same time it was desired to obtain the perithecia in a str1cUy localized area of the culture dish. In what
proportion would albinos be expected to occur among the progeny of' such a cross? Would it be surprising to
find that an the albinos from a single ascus
produced in the cross were of "B" reaction? Explain in some detail.
10. By labeled sketches indicate exactly where karyogamy occurs in Synchytrium, Phytophthora, Rhizopus,
Pyronema, Ustilago and Irpex.
11. Compare Pyrenomycetes, Discomycetes, Rusts, Smuts, and Homobasidiomycetes in regard to the nature and
extent of the dicaryophase.
12. What is a "yeast"? Distinguish between "sporogenous yeasts and "asporogenous yeasts", between "haplobiontic
yeasts" and "diplobiontic yeasts." List four families to which yeasts of various kinds are assigned.
13. Taphrina, Protomyces, Ustilago and Dacrymyces, although not "yeasts" regularly have a "yeast phase" and in
culture may closely resemble yeasts. To what orders and classes do these four genera belong?
14. Suppose that all fungi (Eumycophyta) suddenly disappeared from the earth. Consider the immediate and the
long-range ramifications or this event, on humans.
15. Heterosporangium gracilie incites a common leafspot disease of Iris. Even though had you never heard or this
fungus before, to learn that Heterosporium is a member of the Dematiaceae-Phragmosporae should provide
substantial information about it. What does this tell you?
What is the basis for the belief that the Dermatophytes are closely
related to the Gymnoascaceae?
List several fungi that parasitize insects.
List several fungi that parasitize other fungi and specify the hosts.
19. Forcible discharge of certain reproductive bodies is common in some genera of fungi, e.g." Pilobolus, Nuurospora,
Entomophthora, Urnula, Sphaerobolus, Sporobolomyces, etc. Indicate the order to which each named genus
belongs, and in each case
state what structure it is that is discharged.
List all the orders of fungi (Eumycophyta) in which zoospores are
Name four families of' the Eumycophyta all known members of
which are obligate parasites.
Prepare a dichotomous key to the orders or the
23. List some fungi (Eumycopbyta) that are intracellular parasites.
What kinds of spores are produced by demicyclic rusts? Give an example of a heteroecious
25. Of what special importance is each of the following? Tuber, Polyporaceae, Amanita, Chaetomium, Aspergillus,
26. Certain genera in the Melampsoraceae produce their aecia on pine trees. What are these genera and how can you
distinguish one from another macroscopically on the pine host?