Protozoa And fungi

Question 1

Slime molds belong to which phyla

Water molds belong to which phyla

Which kingdom do they belong to

Answer 1

Myxomycota

Oomycota

Protozoa-little evidence for direct relationship to fungi.

Question 2

Class myxomycetes are known as

Answer 2

Plasmodial slime molds

Question 3

Plasmodial slime molds characteristics

Answer 3

-many diploid nuclei not divided by cell walls
-as it grows, nuclei divide repeatedly and synchronously
-thin streaming masses of protoplasm that creep along in an Amoeboid fashion

Question 4

Feeding of Plasmodial slime molds

Answer 4

-engulf by phagocytosis bacteria, yeast cells, fungal spores and small particles of decayed plant and animals matter

Question 5

How do Plasmodial slime models move

Answer 5

Cytoplasmic streaming

The cytoplasm can be seen to stream outward towards the edge of the plasmodia then slowed stop and stream onwards. This cycle alternated in different veins and the whole cycle repeated once every 3-5 min

Question 6

Plasmodial growth continues as long as…..

What happened if it is not….

Answer 6

There is adequate food supply and moisture available

Plasmodium migrated to an exposed area and enters its reproductive stage when food and moisture are lacking.

Under adverse conditions, the plasmodium will produce fruitifications

Question 7

What happens in fruitifications or fruiting bodies

Answer 7

Meiosis occurs to produce haploid spores.

Meiospores have cell walls that contain cellulose.

Question 8

Myxomycota have what 3 reproductive structure types

Answer 8

Sporangium
Aethalium
Plasmodiocarp

Question 9

Sporangium of Myxomycota

Answer 9

In many species, when the plasmodium stops moving, it divided into a large number of small mounds. Each mound produces a mature sporangium, usually borne at the tip of a stalk.

Question 10

Peridium

Answer 10

A wall that encloses the spore mass
-may vary from delicate, thin and membranous to thick and tough impregnated with lime or refuse matter

Part of sporangium

Question 11

Stalk or stipe of sporangium

Answer 11

Unless the fruiting body is sessile, it it borne by the stalk. Stalks display a diverse range of lengths, thicknesses and colours

Question 12

Hypothallus of sporangium

Answer 12

A layer deposited by the plasmodium at the base of one or more of the fruiting bodies. Often it is continuous under a colony or cluster of sporangia; at other times it forms veins connecting a few fruitions bodies

Question 13

Columella of sporangium

Answer 13

Located at the Center or at the base inside the sporangia. It appears to be an extension of the stalk, and may serve to support the spore mass

Question 14

Capillitium of sporangium

Answer 14

Extensive series of thread-like structures usually present among the spores. These threads are sensitive to changes in humidity and expand and contract, helping to release the spores

Question 15

Spores of sporangium

Answer 15

Very large number of haploid spores are produced in each fruiting body

Question 16

Aethalium

Answer 16

Relatively massive, single chambered, sporangiophores. They are thought to have been formed by complete fusion of large numbers of sporangia during their evolutionary development. No trace of individual sporangial walls are found in most Aethalia

No stalks
No insidiously capitula

Question 17

Plasmodiocarp

Answer 17

Discrete sporangia or aethalia are not produced. Instead, the entire plasmodium may develop into a Plasmodiocarp, which retains the former shape of the plasmodium

Question 18

Spores of Myxomycota

Answer 18

Very small and easily dispersed by the wind
-if they land in favourable habitat they germinate.
-protoplasm may remain Amoeboid or it may develop one or two whiplash flagella.

Question 19

Amoeboid is interchangeable with

Answer 19

Flagellated Swarm cells

Question 20

Amoeboid feeding and multiplying

Answer 20

Ingestion of bacteria and organic material and multiple by mitosis and cell cleavage

Question 21

If the food supply is used up, or conditions are otherwise unfavourable, the amoebae may cease to move and …..

Answer 21

Become round and secrete a thin wall to form a Microcyst

Microcysts can remain viable for a year or more, resuming activity when favourable conditions return

Question 22

After a period of growth, plasmodia are formed by……

Answer 22

The fusion of gametes which are usually genetically different from one another and are derived from different haploid spores.

Gametes are amoebae or flagellate cells playing a new role

Question 23

Oomycota are known as

Answer 23

Water molds or downy mildews

Question 24

The members of phyla oomycota all produce ……

Answer 24

Nonsexual propagative spores that are flagellate (zoospores) and the number, position and type of flagellae provide the means for further breakdown. They do not generate any complex spore-producing organs.

Question 25

Thalli of oomycota

Answer 25

Relatively simple, ranging from a single cell, which is eventually converted into a reproductive structure (holocarpic) to a differentiated cells which is separated into a veg active and reproductive portion. Most complex thallus is a branched coenocytic mycelium.

Question 26

Where do oomycota live

Answer 26

Water or at least require free water for a motile flagellate stage

Question 27

How are oomycota distinguished from chytrids

Answer 27

Exclusively diploid assimilative hyphae -cell walls of these organisms are composed largely of cellulose or cellulose-like polymers, thus differing markedly from the cell walls of the fungi which are made of chitin. They range from unicellular formed to highly branched, coenocytic filamentous ones

Question 28

How do oomycota reproduce

Answer 28

Both sexually and asexually Sexual is Oogamous (egg is large and non motile and Sperm is small and biflagellate). Union results in an oospore, which serves as a resting spore. Asexual is by zoospores that have 2 flagella: one tinsel and one whiplash

Question 29

Order Saproleginales habitat and lifestyle

Answer 29

Aquatic oomycota -water molds -fresh water -saprobic, few are parasitic

Question 30

Sexual reproduction in water molds can occur with male and female sec organs borne on the same individual = Or Male and female sex organs are borne on different individuals

Answer 30

Homothallic - Saproleginales Heterothallic - Achlya

Question 31

Both Saprolegina and Achyla reproduce ……

Answer 31

Both sexually and asexually

Question 32

Order Peronosporales habitat and lifestyle

Answer 32

Primarily terrestrial oomycota Pathogen - plasmopara viticola caused downy mildew on grapes and Phytophthora infestans cases late blight on potatoes

Question 33

Order Saproleginales (water molds) Structure

Answer 33

-profusely-branched coencytic hyphae which forms a colony around decaying organic material in the water -diploid mycelia

Question 34

Saprolegnia sp. -lifestyle -reproduction is mainly

Answer 34

-Parasitic on fresh water fish and fish eggs -asexual

Question 35

Asexual and sexual cycle of Saprolegnia

Answer 35

Asexual: tips of vegatatice hyphae have sporangia which undergo mitosis to produce flagellated primary zoospores. These encyst and then form secondary zoospores, which then encyst and then became vegetative hyphae Sexual: vegetative hyphae have Oogonia on tips. Undergo meiosis to produce oospheres. Antheridia develops from other tips of same inddivual to produce nervous male nuclei. Antheridia grow toward Oogonia and develop tubular processes called fertilization tubes, that penetrate the Oogonia. Male nuclei travel down fertilization tubes to the female nuclei and fuse with them. Thick walled zygote (oospore) is produced. Upon germination, the oospore developed into a hyphae which then produced a sporangium. Homothallic (monoecious)

Question 36

Order Peronosporales (downy mildews) -lifestyle -reproduction stages

Answer 36

-obligate parasite on the aerial parts of higher plants -spores are wind borne, sporangia are not unspecialized hyphae tips, but borne on branched aerial asexual conidiophores, which produce asexual spores called gonidia. -sexual sporangia are borne on sporangiophores. The sporangiophores cover the surface of the leaves and stems of the infected plants, giving them a downy appearance. The entire sporangia are released, then fall to the ground to be picked up by emerging seedlings or are carried on the wind to and on leaves of more mature plants. -if free water is present, the sporangia germinate and release flagellated zoospores. These zoospores swim and enter the plant tissue through open stomata, or any break in the cuticle. The zoospores then Develop into the hyphae which invaded the host tissue.

Question 37

The mycelia of Peronosporales feed ok living cells by the use of

Answer 37

Haustoria Haustoria penetrate the living host cells and absorb nutrients and pass them to the growing hyphae

Question 38

Peronospora parasitica

Answer 38

Downy mildew on crucifers -organism causes infections in mustard, canola, broccoli, cabbage, cauliflower and turnips -diseased plants are detected by their swollen, and distorted stems bearing a white flower or sporangiophores. -the leaves the fungus is associated with a yellowish patch on the upper surface and the formation of white sporangiophores beneath. -invading mycelia destroy the host tissue.

Question 39

Downy mildews do not occur in the _____ habitat and the motile zoospore stage is all but _______ in Peronopsora

Answer 39

Aquatic Absent

Question 40

Phytophthora infestans

Answer 40

Late blight on potatoes -caused by a fungus-like organism called Phytophthora infestans which is a destructive parasite of potatoes In potatoes the disease can cause rapid destruction of foliage and tubers.

Question 41

Is Phytophthora infestans Homothallic or heterothallic

Answer 41

Heterothallic, requiring presence of two different strains for sexual reproduction to occcur Whether a strain will be male or female is under nutritional control.

Question 42

asexual reproduction of Phytophthora infestans

Answer 42

Highly efficient and can result in rapid infestation of crops.

Question 43

How does Phytophthora infestans work

Answer 43

Branched sporangia emerge from the leaves, commonly through the stomata, and hygroscopic twisting of the sporangiophore occurs with changes in humidity, flicking off the sporangia into the wind. When wind-borne sporangia land on a moist leaf surface, they germinate by production of germ-tubes or at cooler temps by production of motile zoospores that may be dispersed further by swimming and splashing. -infection of new host plant may take place inside 2 hours and production of new sporangia are sensitive to drying.

Question 44

Spells of ___________ price the rapid spread and crop destruction in Irish famines of Phytophthora infestans

Answer 44

Cool, damp weather

Question 45

Symptoms of Phytophthora infestans

Answer 45

dark lesions on stems or leaves resembling those caused by frost. -under moist conditions: whitish masses of sporangia appear on the lesions. -the tubers develop brown or purple blotches on skin, which spreads into the tuber flesh. Late blight can be a rapid and destructive disease: fields appear to be healthy but contain low incidence of disease, can be devastated within days

Question 46

Most fungi are multicellular filamentous structures, but yeasts are

Answer 46

UnicellulR

Question 47

Hyphae Mycelium

Answer 47

Fungal filament Mass of hyphae from one organism

Question 48

Septae

Answer 48

Cross walls of fungal hyphae

Question 49

Septate Aseptate or coenocytic

Answer 49

Hyphae with cross walls Hyphae lacking cross walls

Question 50

Functionally coenocytic

Answer 50

Even in hyphae with septae, there is movement of materials through a central pore in each septum. Protoplasm and nuclei can move from cell to cell making them functionally coenocytic

Question 51

Ascomycota Intraseptal pores

Answer 51

Large enough to accommodate passage of nuclei from cell to cell.

Question 52

Nuclei of fungal hyphae are _____

Answer 52

Haploid

Question 53

All fungi have cell walls composed primarily of Primary storage polysaccharide in fungi

Answer 53

Polysaccharide chitin Glycogen

Question 54

Rhizoids

Answer 54

Specialized hyphae to anchor some types of fungi to substrate

Question 55

Haustoria

Answer 55

Specialized hyphae of parasitic fungi which penetrate the plasma membrane of other organisms also that the fungus can absorb directly the cell contents of the host

Question 56

Fungi reproduce through the formation of either _________ spores Most fungi have _____ spores but chytrids are an exception

Answer 56

Sexual or asexual Non-motile

Question 57

Asexual reproduction in fungi is most commonly by ____ formation, with spores either produced in _______ or as single cells or chains of spores in ______ which arise from _____. In some fungi, the hyphae can reproduce asexually via _______

Answer 57

Spore Sporangia Conidia Hyphae Fragmentation

Question 58

Fungal sexual reproduction consists of what phases

Answer 58

Plasmogamy-fusion of protoplasts Karyogamy - fusion of nuclei Meiosis

Question 59

Dikaryon

Answer 59

Two nuclei The fusion of nuclei does not necessarily follow immediately after plasmogamy and hence the two haploid nuclei can exist together, unfused.

Question 60

If Karyogamy is delayed long enough, the paired haploid nuclei each may…..

Answer 60

Begin to divid mitotically and produce a dikaryotic mycelium. The haploid nuclei with eventually fuse within a fruiting body to form a diploid nucleus which quickly exhibits Zygotic meiosis and the only diploid phase in the life cycle is the zygote

Question 61

Members of zygomycota produce ______ as their sexual reproductive spores

Answer 61

Zygospores Heavy-Walled zygote not associated with an oogonium.

Question 62

Ascomycota produce ________ within a special structure termed an ______

Answer 62

Ascospores Ascus

Question 63

Baidiomycota produce _______ in a ______

Answer 63

Basidiospores Basidium

Question 64

Phylum Chytridomycota or chytrids Habitat and lifestyle

Answer 64

Mainly aquatic but some live in damp soil Many are Parasitic on algae, fungi, mosses and higher plants

Question 65

Chytrids cell walls composition

Answer 65

Mostly of chitin

Question 66

Zoospores and gametes of chytrids have

Answer 66

-one posterior whiplash flagella at maturity. Likely they branched off from other fungal lines and their flagellates condition represents the retention of primitive characteristic destined from a flagellated protist ancestor.

Question 67

Chytrids consist of forms with no true ___ and most are ______

Answer 67

Mycelium Coenocytic

Question 68

During reproduction, what do chytrids do

Answer 68

Whole organism is transformed into a reproductive unit

Question 69

Synchytrium endobioticum -what phyla -common name

Answer 69

Chytriomycota Black wart disease of potato

Question 70

Synchytrium endobioticum

Answer 70

Obligate parasite which causes black wart disease of potatoes. Like many other specialized parasites it induces abnormal growth (hypertrophy) of infected cells. The infested tubers have large-wart like growth on them. Although there have been bad outbreaks of this disease in Newfoundland, it is not of economic importance today due to the strict control over the import of infected seed potatoes. Produced thick walled resting spores in the wafted tuber. Also formed zoospores which have a very short range of operation in the aqueous phase of soil.

Question 71

Synchytrium endobioticum is ______ and ________ (whole cell becomes reproduce structure)

Answer 71

Unicellular Holocarpic

Question 72

Only member of the Fungi in which motility have been retained

Answer 72

Order Blastocladiales

Question 73

Blastocladiomycetes tend to be ______, in which there is an extensive vegetative growth habit in which some of the organism participated in reproduction (sexual or sexual)

Answer 73

Eucarpuc

Question 74

Members of _______ exhibit complete alternation of generations between a haploid gametophyte and a diploid sporophyte

Answer 74

Blastocladiales

Question 75

Allomyces forms a ______ in both generations

Answer 75

Cottony mycelia

Question 76

Gametophytes of allomycetes

Answer 76

Tandem paired gametangia that terminate the hyphae such that the terminal gametangia (usually smaller of the two) is male and it produces the smaller of the two motile ansiogametes. The larger proximal gametangia release larger motile ansiogametes.

Question 77

Sporophyte of Allomyces

Answer 77

Produced terminal single sporangia within which meiosis occurs and zoospores are formed Released zoospores develop into gametophyte

Question 78

Allomyces sp. -habitat -alternation of generations?

Answer 78

-Water mold distributed in soil throughout the world and particularly in warmer climates -yes, diploid filamentous sporothallus produces spores and a haploid filamentous gametothallus produces gametes

Question 79

The filamentous cells of Allomyces grow without ……, and divide in a _________

Answer 79

Limitation in length Dichotomous pattern that results in a geometric mycelium

Question 80

Hyphae of Allomyces

Answer 80

Hyphae are separated by pseudosepta that allow free circulation of intracellular materials along the filaments. The reproductive structures at the end of hyphae are isolated by compete septa.

Question 81

Allomyces macrogynus is a ______ fungi which exhibits two very similar looking dichotomously branching coenocytic thallus while immature. However, once thalli have reached maturity…..

Answer 81

Saprobic homothallic -orange male gametangia growing Epigynously on the clear female gametangia make the haploid gameothallus differentiator from the diploid sporothallus that produces terminal sporangia.

Question 82

Gametangia of Allomyces produce what

Answer 82

Small haploid posterior, uniflagellate gametes. The female gametes is much less motile than male and diffuses a hormone to attract the male gamete. Upon gamete fusion, a large posterior biflagellate zygote is produced that encyst to form the sporothallus

Question 83

On a single sporothallus of Allomyces, what can be produced

Answer 83

Pigmented resistant sporangia and clear zoosporangia Thick-Walled melanin pigments resistant sporangia are the site of meiosis and release haploid zoospores into an exit papilla prior to release into the water. Haploid zoospores later encyst to form the gametothallus

Question 84

Phylum Zygomycota -lifestyle

Answer 84

Saprobic-living on decaying plant or animal material in the soil. Some may be parasites on plants, insects or small soil animals.

Question 85

Rhizopus stolonifera -common name -what does it cause

Answer 85

Bread mold Causes black bread mold that forms cottony masses on the surface of moist bread exposed to the air.

Question 86

Mycelium of Rhizopus stolonifera

Answer 86

Composted if 3 different types of haploid hyphae -bulk of mycelium consists of rapidly growing hyphae that are coenocytic and aseptate. Arching hyphae called stolons are formed. Stolons form this puts wherever their tips come in contact with the substrate.

Question 87

Sporangia of Rhizopus stolonifera

Answer 87

Form on the tips of sporangiophores, which are erect branched formed directly above the rhizoids. Each sporangium brings as a swelling into which a number of nuclei flow and are eventually cut off from the sporangiophores by the formation of a septum. Sporangium become black as it matures giving the mold its colour. Each spores when liberated can germinate into a new mycelium

Question 88

Sexual reproduction of Rhizopus stolonifera

Answer 88

Occurs between different mating strains. -when the two strains are in close proximity, hormones are produced that chase their hyphae tips to come together and develop into gametangia, which become separated from the rest of the fungal body by the formation of septa. -walls between two touching gametangia dissolve and the two multinucleate protoplasts comes together. The fused nuclei form a young zygospores with several diploid nuclei.

Question 89

Zygospores of Rhizopus stolonifera

Answer 89

Develop thick, rough black coat and become dormant, often for several months. Meiosis occurs at the time of germination. The zygospore cracks open ad produced a sporangium that is similar to the asexually produced sporangium and the life cycle begins again

Question 90

Rhizopus rot is caused by…..

Answer 90

Rhizopus stolonifera Destructive to harvested fruit -most commonly affects fruit in storage, during transit and at the marketplace. -ripe fruit of peaches, nectarines, sweet cherries and plus are most susceptible. -causes fuzzy appearance