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EXAMINATION & EXERCIZES #1

 

For The  SCHIZOMYCOPHYTA, AMOEBOZOA & ZYGOMYCOTA

 

(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.]

 

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

 

 

1.  Assign each of the following genera to its proper kingdom and order:

 

Absidia = ______________________________________________

Achlya = ______________________________________________

Albugo = ______________________________________________

Allomyces = ____________________________________________

Aphanomyces = _________________________________________

Basidiobolus = _________________________________________

Basidiophora = _________________________________________

Circinella = ____________________________________________

Myzocytium = ___________________________________________

Physoderma = ___________________________________________

Phytophthora = __________________________________________

Podochytrium = __________________________________________

 

2.  For each of the entries in the column at the left select from the column at the right the one genus that best fits that

        item, and enter the number of the selected organism in the appropriate blank:

 

 

_____ parasite on Rhizopus

_____ Late Blight of Potato

_____ trophocyst

_____ stolon

_____ merosporangium

_____ sporangiolum

_____ phototropism

_____ catenulate conidia

_____ holocarpic Zygomycota

_____ conidiophores may arise from "hyphal

               bodies

_____ forcible ejection of multispored sporangia

_____ conidiophores (sporangiophores)

               emerge through stomata of host

               and of determinate growth

 

 

 1.  Phytophthora

 2.  Peronospora

 3.  Pilobolus

 4.  Syncephalis

 5.  Albugo

 6.  Thamnidium

 7.  Allomyces

 8.  Entomophthora

 9.  Absidia

10. Synchytrium

 

 

 

 

 

 

 

 

 3.  Classify the following genera:

 

Class:  _____________________________

Subclass:  __________________________

Order:  _____________________________

Family:  ____________________________

Genus:            Synchytrium

Class:  _____________________________

Subclass:  __________________________

Order:  _____________________________

Family:  ____________________________

Genus:            Pilobolus

 

 

 

4.  Which of the following genera are comparable in that a single oosphere is differentiated in the oogonium, with periplasm around it: 

 

Aphanomyces    Achlya    Pythium    Albugo    Peronospora

   Monoblepharis    Phytophthora    Allomyces    Bremia

 

5.  In the subclass Biflagellatae of the Zygomycota underline which of the following apply:

 

No forms are holocarpic

Zoospores may be facultative gametes.

All flagellated cells are zoospores.

Gametic union usually occurs within the thallus.

All species are confined to aquatic habitats.

Fertilization tubes are of common occurrence.

Detachable zoosporangia re found in some genera.

No forms are obligately parasitic.

 

6.  The peculiar elongated sporangia of Syncephalis are called ________________________.

 

7.  Underline the correct statement:  The conidiophores of the Downy Mildews are (determinate) (indeterminate)

         In growth.  (All)  (Most)  (No) downy mildew fungi are obligate parasites.  If the conidium of a downy mildew

         germinates by production of zoospores, this is known as (direct)  (indirect) germination.  Diplanetism (is)

         (is not) encountered in downy mildews.

 

         Fill in the blanks:  Four genera of Downy Mildews are: _____________________,  ____________________, 

             _____________________,  _____________________, 

 

8.  Underline the correct genus:  Delimitation and/or maturation of zoospores in a "vesicle" is typical of

(Peronospora)  (Pythium)  (Aphanomyces)  (Saprolegnia)  (Lagenidium)  (Phytophthora).

 

9.  In the genus _________________ of the Mucorales, Sporangiophores are typically borne on the stolon arch and

            zygospores are surrounded by appendages growing from one or both suspensors.

 

10.  Underline the correct statement:  Sporangiola are found in (Thamnidium)  (Pilobolus)  (Circinella).  These are

           (few-spored)  (many-spored)  (commonly detachable) sporangia  (with)  (without)  a columella.

 

11.  Underline the correct statement:  The fact that the conidia of Peronospora are not known to germinate by the

        formation of zoospores indicates that this is  (a primitive)  (an advanced)  genus in the Peronosporaceae.

 

12.  Fungi that produce zygospores  (may also produce)  (never produce)  zoospores.

 

13.  Underline the correct statement:  The genera of the Peronosporaceae are separated mainly on the basis of

         (the number of oospores per oogonium)  (the form of the conidiophores)  (the size and shape of conidia)

         (the type or pattern of sculpturing on the oospore wall).

 

14.  Underline the correct statement:  Aphanomyces and Allomyces (are)  (are not) closel-related members of the

         Zygomycota.  (They belong)  (They do not belong) to the same subclass.

 

For the following fill in the blanks or underline the correct statements:

 

15.  Species of the genus Entomophthora (can)  (cannot) be grown in vitro on agar media.

 

16.  A rot of sweet potatoes, apples, etc. is incited by (Mucor)  (Syzygites)  (Rhizopus)  (Basidiophora).

 

17.  Forcible discharge of conidia is a feature of (all)  (a few)  (most)  members of the Entomophthorales.

 

18.  A cottony, slightly yellow growth of mold was noted on a gill fungus in the forest.  No vegetative reproductive

        structures could be found on close examination, but many large zygospores were present and these were borne

        between suspensors attached to coarse yellow zygophores.  The observations indicate that the mold was

        ______________________.

 

19.  "Damping Off" diseases are regularly incited by soil-inhabiting species of the genus ______________ of the

        Zygomycota.

 

20.  (All)  (Most)  true fungi that produce zoospores are members of the Zygomycota.

 

21.  Columellate sporangia may be found in the following genera of the Mucorales: ____________________, 

 

         ____________________,  ____________________,  ____________________.

 

22.  Two Zygomycota fungi that typically grow on dung are _________________, and __________________.

        Such "dung-inhabiting" forms are technically known as __________________________.

 

23.  A certain Zygomycota fungus has the following characteristics:

 

          A.  It is aquatic.   B.  It has a branching coenocytic mycelium, the hyphae of which usually have regularly

          arranged vacuoles.  C.  it produces clavate, non-detachable zoosporangia.  D.  From the male gametangium

          small flagellated male gametes called "antherozoids" are released into the water where the fungus is growing. 

          E.  an antherozoid enters the female gametangium to unite thee with a large non-motile egg.

 

         This fungus belongs to the order __________________________ in the subclass _____________________

          of the Zygomycota.

 

24.  The sporangiophores of (Phycomyces)  (Circinella)  (Plasmopara)  (Pilobolus)  (Albugo)  are strongly

        phototropic.

 

25.  The Mucorales (are)  (are not)  prominently represented in the fungal flora of the soil.

 

26.  Heterothallism in the Mucorales was discovered by  (Harper)  (Thaxter)  (Blakeslee)  (Millardet)  (de Bary) about

         (1850)  (1875)  (1900)  (1925).

 

27.  Stolons are produced in the following genera of the Mucorales:  (Cunninghamella)  (Circinella)  (Absidia)

         (Syzgites)  (Pilobolus)  (Rhizopus)  (Mucor).

 

28.  Downy mildew fungi all form haustoria.  One of the largest haustoria is produced by what species? ________.

 

29.  In the Entomophthorales most species of the genera ________________ and _________________ are parasitic

         on insects.  Two members of the Entomophthorales that do not parasitize insects are ____________________

         and _____________________.

 

30.  In a homothallic Mucorales such as Syzgites a culture grown from a single sporangiospore (might be expected to) 

        (would not be expected to) form zygospores.

 

26.  The Mucorales  (are)  (are not) prominently represented among the soil fungal inhabitants.

 

27.  Heterothallism in Mucorales was discovered by (Thaxter)  (Blakeslee)  (deBary) about  (1875)  (1905)  (1925).

 

28.  Phytophthora infestans belongs to the family ___________________ in the order ____________________.  It 

           (is)  (is not) an obligate parasite.  It incites a disease of _____________________ known as ______________. 

           Conidiophores of P. infestans are of  (determinate)  (indeterminate) growth and  (are unbranched)

           (branch dichotomously)  (branch monopodially).

 

29.  In Albugo candida the mature oospore is (uninucleate)  (multinucleate).  When an oospore of A. candida

          germinates  (a short conidiophore emerges)  (mycelium grows out)  (The endospore wall layer forms a vesicle)

          (zoospores are released)

 

30.  In a homothallic mucor such as Syzygites a culture grown from a single sporangiospore  (might be expected to) 

          (would not be expected to) form zygospores.

 

31.  Fungi that produce zygospores  (may also produce)  (never produce) zoospores.

 

32.  Massospora belongs to the order __________________ in the Sub-class ______________________ of the

          Zygomycota.  The conidia of this fungus  (are)  (are not) forcibly discharged.  Two other genera belonging to the

          same order are  _________________________ and _______________________.

 

33.  Some species of all species of the following genera are coprophilous:  (Pythium)  (Basidiophora)  (Basidiobolus)

           (Mucor)  (Syncephalis)  (Pilobolus)  (Completoria).

 

34.  Sporangiola are found in  (Thamnidium)  (Pilobolus)  (Absidia).  These are  (few-spored)  (many-spored)

          (usually detachable)  sporangia   (with)  (without) a columella.

 

35.  The sporangiophores of  (Circinella)  (Phycomyces)  (Pilobolus)  (Plasmopara)  (Albugo)  are strongly

           phototropic.

 

36.  The fact that the conidia of Peronospora apparently never germinate by formation of zoospores indicates that it

           is  (an advanced)  (a primitive) genus in the Peronosporaceae.

 

37.  The haustoria of  Plasmopara viticola are  (smaller)  (larger) than those of Peronospora parasitica.

 

38.  Cunninghamella  (is)  (is not)  regarded as one of the most advanced genera in the Mucorales.

 

39.  Delimitation and/or maturation of zoospores in a vesicle extruded from the sporangium is typical of 

           (Peronospora)  (Pythium)  (Saprolegnia)  (Albugo)  (Lagenidium)  (Phytophthora)  (Aphanomyces).

 

40.  Allomyces and Aphanomyces  (are)  (are not)  closely-related genera of the Zygomycota.    (They belong)

           (They do not belong)  to the same Sub-class.

 

41.  Members of the genus Entomophthora  (can)  (cannot) be grown in vitro on agar media.

 

42.  Oospores occur in the following:  (Allomyces)  (Leptomitales)  (Aphanomyces)  (Pythium)  (Urophlyctis)

          (Sporodinia)  (Basidiophora)  (Saprolegniales)  (Zygomycetes)  (Phytophthora).

 

43.  The peculiar elongated sporangia of Syncephalis are called _____________________.

 

44.  In the genus _____________________ sporangiophores are typically borne on the stolon arch and zygospores

           are surrounded by appendages growing from suspensors.

 

45.  The sporangium of Saprolegnia is considered to be homologous with  (the conidiophore)  (the conidium) 

          (a zoospore)  (a germ tube)  of Albugo.  In Saprolegnia there is   (lateral)  (internal)  (no)  proliferation of the

          sporangia.  Diplanetism  (is encountered)  (is not encountered)  in this water mold.

 

46.  The genera of the Peronosporaceae are separated mainly on the basis of   (number of oospores per oogonium)

          (form of the conidiophores)  (size and shape of conidia)  (type of sculpturing on the oospore).

 

47.  Stolons are produced in the following genera of the Mucorales:    (Phycomyces)  (Mucor)  (Rhizopus) 

          (Pilobolus)  (Sporodinia)  (Absidia)  (Circinella)  (Cunninghamella).

 

48.  Catenulate conidia are produced in  (Phytophthora)  (Pythium)  (Albugo).

 

49.  Conidiophores of the Downy Muldews are  (determinate)  (indeterminate) in growth.  Four genera of Downy

          Mildews are  _______________,  _________________,  _______________,  _________________.  (All) 

          (Most)  (No)  downy mildew fungi are obligate parasites.  If the conidium of a downy mildew germinates by

          production of zoospores, this is called   (direct)  (indirect) germination.  In the downy mildews the zoospores

          have (one flagellum)  (two flagella).

 

50.  The following genera are similar in that a single oosphere is differentiated in the oogonium with periplasm present

          around this oosphere:    (Aphanomyces)  (Achlya)  (Sapromyces)  (Albugo)  (Peronospora)  (Pythium) 

          (Monoblepharia)  (Allomyces).

 

51.  In the Biflagellatae subClass of the Zygomycota,  (plasmogamy always occurs within the fungus thallus)

           (fertilization tubes are of common occurrence)  (no forms are holocarpic)  (zoospores may be facultative

          gametes)  (detachable zoosporangia are found in some genera)  (all species are confined to aquatic habitats).

 

52.  Assign each of the following genera to its proper order:

 

Myzocytium =

Physoderma =

Sapromyces =

Achlya =

Basidiosphora =

Circinella =

Albugo =

Pythium =

 

_____________________________

_____________________________

_____________________________

_____________________________

_____________________________

_____________________________

_____________________________

_____________________________

 

 

53.  For each of the entries in the left column select from the column at the right the one fungus that best fits that

          entry, and enter the number of the selected organism in the appropriate blank.

 

ญญ____ Catenulate conidia = zoosporangia.

____ Production of antibiotics

____ Parasite on Mucor or Rhizopus

____ Late Blight of Potato

____ Millardet

____ Forcible ejection of multispored sporangia

 

____ Conidiophores (sporangiophores) emergent thru'

         stomata of host & of determinate growth

 

____ Holocarpic Zygomycota

____ Phototropism

____ Stolon

____ Subsporangial vesicle

 

 1.  Phytophthora

 2.  Peronospora

 3.  Olpidium

 4.  Physoderma

 5.  Plasmopara

 6.  Pilobolus

 7.  Syncephalis

 8.  Albugo

 9.  Pythium

10.  Entomophthora

11.  Streptomyces

12.  Absidia

 

54.  Classify the following genera:

 

Class:  _____________________________

Subclass:  __________________________

Order:  _____________________________

Genus:            Bremia

Class:  _____________________________

Subclass:  __________________________

Order:  _____________________________

Genus:            Basidiobolus

 

 

Class:  _____________________________

Subclass:  __________________________

Order:  _____________________________

Genus:            Aphanomyces

Class:  _____________________________

Subclass:  __________________________

Order:  _____________________________

Genus:            Sporodinia

 

 

 

55.  A particular Zygomycota fungus has the following characteristics:

 

          a.  it is aquatic, b.  it has a branching coenocytic mycelium, the hyphae of which usually have regularly arranged vacuoles, c.  it produces clavate, non-detachable zoosporangia, d.  from the male gametangium small flagellated male gametes, called "antherozoids" are released into the water where the fungus gorws, e.  an antherozoid enters the female gametangium to unite there with a large non-motile egg.

 

          This fungus might be ___________________________ or ________________________________, but

             belongs to the order ____________________________ in the Subclass __________________________.