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EXAMINATION & EXERCISES #4

For The AMOEBOZOA, ZYGOMYCOTA, ASCOMYCOTA & BASIDIOMYCOTA

(Contact)

[For answers please also refer to: Alexopoulos, C. J., C. W. Mims and M. Blackwell.

1996. Introductory Mycology. John Wiley and Sons, New York.]

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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 ______________________.,

2. Distinguish between "periplasm" and "epiplasm".

3. 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:

________ Acervulus ________ Aecia usually on conifers ________ Arthrospores ________ Blue stain ________ Capillitmum ________ Coremium ________ Cystosorus ________ Damping off ________ Diplanetism ________ Endoconidia ________ Epiphram ________ Ergot ________ Flagellated male gamete fertilizes non-motile egg ________ Holocarpic phycomycete ________ "Hyphae" extremely fine, common in soil ________ Late Blight of Potato ________ Merosporangium ________ Notorious wood destroyers ________ Parasite on insects ________ Parasite on mushrooms ________ Parasite on rusts ________ Parasitic homobasidiomycete w/o basidiocarp ________ Peach Leaf Curl ________ Penicillin ________ Phototropism ________ Pseudoplasmodium ________ Rot of oranges ________ Saddle-shaped apothecium ________ Skin infection ________ Slime mold with exogenous spores ________ Sooty molds ________ Soredium ________ Stalked teliospores ________ Subterranean ascocarp ________ Tar Spot ________ Turbinate cell ________ Vertically-septate basidium ________ Volva ________ Yeast multiplying by fission ________ Y-shaped basidia

1. Arcyria 2. Penicillium chrysogenum 3. Meliola 4. Endomyces 5. Thielaviopsis 6. Darluca 7. Olpidium 8. Rhytisma 9. Tremellales 10. Ceratostomella 11. Claviceps 12. Cyathus 13. Hypomyces 14. Streptomyces 15. Dermatophytes 16. Polysphondylium 17. Ithyphallus 18. Melampsoraceae 19. Saprolegnia 20. Polyporaceae 21. Tuber 22. Pythium 23. Pucciniaceae 24. Penicillium italicum 25. Phycomyces 26. Monoblepharis 27. Syncephalis 28. Taphrina 29. Melanooniales 30. Phytophthora 31. Massospora 32. Exobasidium 33. Lecanorales 34. Helvella 35. Stilbaceae 36. Dacryomyces 37. Ceratiomyxa 38. Spongospora 39. Urophlyctis 40. Schizosaccharomyces

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.

7. 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?

12. What is the basis for the belief that the Dermatophytes are closely related to the Gymnoascaceae?

17. List several fungi that parasitize insects.

18. 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.

20. List all the orders of fungi (Eumycophyta) in which zoospores are found.

21. Name four families of' the Eumycophyta all known members of which are obligate parasites.

22. Prepare a dichotomous key to the orders or the Heterobasidiomycetes.

23. List some fungi (Eumycopbyta) that are intracellular parasites.

24. What kinds of spores are produced by demicyclic rusts? Give an example of a heteroecious demicyclic rust.

25. Of what special importance is each of the following? Tuber, Polyporaceae, Amanita, Chaetomium, Aspergillus,

Ashbya

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?