MICRO LEC: INTRO TO MYCOLOGY PT1 Flashcards
1
Q
Study of fungi
Also important in food chain because they can decompose ded plant matter
FQ: OUT OF 100,000 species of fungi how many are pathogenic to humans and animals?
A
Mycology
fq: 200
2
Q
They are Chemoheterotrophs; They are multicellular except ________?
fq: What are chemoheterotrophs?
How do they reproduce?
A
Fungi
yeast
FQ: requiring organic compounds for energy and carbon
They reproduce through sexual and asexual spores
3
Q
non-photosynthetic heterotrophs which produce exoenzymes and obtain nutrients by absorption
A
Eukaryotic
4
Q
(e.g. dermatophytes causing ringworms)
A
Parasitic
5
Q
(decomposition of organic matter, causes sporadic opportunistic infections in animals)
A
Saprophytic
6
Q
(obligatory association with other microorganisms; non-pathogenic)
A
Mutualistic
7
Q
cause localized lesions
A
Overgrowth of yeasts (often commensals)
8
Q
Can tolerate high osmotic pressures and acidic environments as low as pH 5.0 (optimum pH is about 6)
A
Fungi
9
Q
Optimum temp. for growth of 20-30C; pathogenic ___ causing systemic mycoses can tolerate 37C
A
Fungi
10
Q
cell type of fungi
A
Eukaryotic
11
Q
cell type of bacteria
A
Prokaryotic
12
Q
cell membrane of fungi
A
Sterols present
13
Q
cell membrane: bacteria
A
Sterols absent; except in mycoplasma
14
Q
cell wall: fungi
A
glucans; mannans; chitin (no peptidoglycan)
15
Q
cell wall: bacteria
A
peptidoglycan
16
Q
Spores: fungi
A
sexual and asexual reproductive spores
17
Q
spores: bacteria
A
endospores (not for resproduction); some asexul resproductive spores
18
Q
metabolism: fungi
A
limited to heterotrophic; aerobic, facultative anaerobic
19
Q
metabolism: bacteria
A
heterotrophic; autotrophic; aerobic; facultatively anaerobic; anaerobic
20
Q
Two main morphological fungal forms
A
Yeast vs. Molds
21
Q
multicellular; vegetative and reproductive phases are two distinct phases; can grow as branching filaments called hyphae
A
Molds
22
Q
Unicellular; the same cell function in vegetative growth (asexual) as well as in sexual reproduction; oval or spherical appearance
A
Yeast
23
Q
a mass of threadlike filaments which combine to make up the fungal mycelium
A
Hyphae (singular: hypha)
24
Q
In most molds, the hyphae contain cross-walls called _______ (singular: septum), which divide them into uninucleate cell-like units - _________
A
septa (singular: septum)
septate hyphae
25
in few class of fungi, the hyphae contain no septa and appear as long, continuous cells with many nuclei
Coenocytic hyphae
26
Impart rigidity and osmotic stability
FQ: Mainly composed of ?
Hyphal cell wall
fq:carbohydrate components including chitin micromolecules with cellulose cross- linkages
27
In yeasts, Hyphal cell wall contain
protein complexed with polysaccharides
28
Hyphal cell wall has Bilayer cell membrane, the predominant sterol is ________ in contrast to cholesterol
ergosterol
29
portion of hypha that obtains nutrients
Vegetative hypha
30
portion concerned with reproduction; projects above the surface of the medium on which the fungus is growing; often bear reproductive spores
Reproductive/aerial hypha
31
Nonfilamentous, unicellular fungi
Spherical or oval
Frequently found as a white powdery
coating on fruits and leaves
Yeasts
32
Explain budding
Parent cells forms a protuberance (bud) on its outer surface
Bud elongates and parent cell’s nucleus divides
One nucleus migrates into the bud
Cell wall material laid down between the bud and parent cell
But eventually breaks away
33
Some yeasts produce buds that fail to detach themselves. These buds form a short chain of cells called ?
pseudohypha
34
-If oxygen is present, yeasts perform aerobic respiration to metabolize carbohydrates into carbon dioxide and water
-If oxygen is absent, they ferment carbohydrates and produce ethanol and carbon dioxide.
-This fermentation is used in the brewing, wine-making and baking
facultative anaerobic growth in yeast
35
-Some pathogenic species of fungi can exhibit dimorphism (two forms)
-Moldlike form- produce vegetative and aerial hyphae
-Yeastlike form- reproduce by budding
Dimorphic Fungi
36
Dimorphism is temperature dependent; give the temperature, yeast and mold grow.
At 37C, the fungus is yeastlike
At 25C, it is moldlike
37
-Elongation at tips
-When a fragment breaks off, it can elongate to form a new hypha
Growth of a Hypha
38
-Large colonies with growth and extension of hyphae at their peripheries
-In some species, mature elements at the center of colonies produce aerial hyphae that facilitates dispersal of mature spores (e.g. conidia and sporangiospores)
Colony formation of Molds
39
are formed only by fungi in the phylum Zygomycota
Sporangiospores
40
multicellular structures
called microconidia are produced
dermatophytes
41
are formed from the disintegration of hyphae within keratinized structures
Arthroconidia
42
-Asexual division is by budding
-Daughter cells separate from parent cells after the formation of a cross-wall at the point of budding
-Colonies are soft, smooth and round
Colony formation of yeasts
43
Different Classifications of Fungi
Ascomycota
Basidiomycota
Zygomycota
Fungi imperfecti (Deuteromycetes)
44
These are all teleomorphs, which produce both sexual and asexual forms
Ascomycota, Basidiomycota, zygomycota
45
T/F Although most of vetrinary importance are deuteromycetes, some fungi in each of the theree phyla can also producw disease in animals
True
46
include the familiar bread mold, Rhizopus stolonifer, which rapidly propagates on the surfaces of breads, fruits, and vegetables
Zygomycetes
47
“conjugation fungi”
Zygomycota
48
Asexual and sexual spores of zygomycota?
Asexual spores: sporangiospores
Sexual spores: zygospor
49
-Also called sac fungi
-Septate hyphae mostly but unicellular yeast may form pseudomycelium
Ascomycetes
50
Ascomycetes Spore are produced in
ascia
51
Ascomycetes septa possess central pores called
septal pores
52
Ascomycetes Fertilization occurs in two steps
plasmogamy and karyogamy
53
Also called club fungi
Most advanced and most commonly seen
Basidiomycetes
54
Basidiomycetes Reproduce _______ by ____________ most common decomposers of wood
asexually
basidium
55
-Also known as fungi imperfecti
-Artificial class of fungi
-Some members belong to both ascomycetes and basidiomycetes
Reproduce only by asexual spores (e.g. conidia formation)
Deuteromycetes
56
include common bread mold (Rhizopus) and other food spoilage
Zygomycetes
57
sac fungi; include fungi that cause Dutch elm disease and rye smut (ergot)
Ascomycetes
58
club fungi; include common mushroom
Basidiomycetes
59
also known as Fungi Imperfecti, include most of the disease-causing fungi such as those causing ring worms (dermatophytes).
Deuteromycetes
60
sexual Fungal Reproduction
Meiospores
61
asexual fungal reproduction
Mitospores
62
can reproduce asexually by fragmentation of their hyphae
Filamentous fungi
63
Different Types of Asexual Spores:
Zoospores
Sporangiospores
Chlamydospores
Blastoconidia
Oidia
Conidia
Arthroconidia
Macroconidia and microconidia
64
motile spores; presence of flagella which help in swimming
Zoospores
65
singles cell spores formed within sacs (known as sporangium) formed at the end of a special hypha (known as sporangiophore); non-motile; dispersed by air.
Sporangiospores
66
thick-walled which contain storage products, single cell spores formed from cells of the vegetative hyphae by accumulation of protoplast and secretion of thick wall
Chlamydospores
67
conidia which are produced by budding as in Candida albicans
Blastoconidia
68
formed under adverse conditions; individual cells separated from hyphae; small yeast-like cells
Oidia
69
small or large, single cell spores formed at the tips or sides of a fungal hyphae conidiophores. Ex. Penicillin, Aspergillus
Conidia
70
spores which are formed and subsequently released during the process of hyphal fragmentation. Spores may be formed successfully as in dermatophytes. (A) or with intervening empty cells as in Coccidioides immitis (B)
Arthroconidia
71
large and small multi-celled conidia which are produced by dermatophytes in culture; lack mitochondria
Macroconidia and microconidia
72
Formation of spores
Fungal Reproduction
73
Methods of asexual reproduction
Budding
Single fission
Fragmentation
Spore formation
74
three phases of sexual reproduction
Plasmogamy
Karyogamy
Meiosis
75
The process of sexual reproduction: fusion of protoplasm
Plasmogamy
76
The process of sexual reproduction : fusion of nucleus
Karyogamy
77
The process of sexual reproduction: reductional nuclear division; Diploid nucleus reduced to 4 haploid nucleus
Meiosis
78
Various methods by which compatible nuclei are brought together in plasmogamy. Some are:
Gametic copulation
Gamete-gametangial copulation
Gametangial copulation
Somatic copulation
Spermatization
79
motile gametes
Planogametes
80
fusion of two gametes, one or both of which are motile
Planogametic copulation
81
Three different types of planogametic copulation
Isogamy
Anisogamy
Oogamy/ Heterogamy
82
morphologically similar but compatible type of gametes unite to fom a motile zygot e.g., Synchytrium
Isogamy
83
Union of larger gamete with another smaller gamete. The resultant zygote is motile; the zygote resulting from isogamous or anisogamous planogametic copulation forms a ‘resting sporangium’; e.g., Blastocladiales
AnisogamyAnisogamy
84
a non-motile female gamete (oosphere) is fertilized by a motile male gaete. This results in the formation of oospores, a resistant structure and resting spore; Oospores germinate and produce mycelium directly; e.g., Chytridiomycetes
Oogamy/ Heterogamy
85
In this method the male gamete (antheridium) and the female gamete (oogonium) come in contact and one or more nuclei fom the male gamete enter the female gamete, oogonium dissolved in the intervening wall through a pore or through a fertilization tube
Gametangial contact
86
This is a process of fusion of entire contents of the two mating gametangia
Gametangial copulation
87
two types Gametangial copulation
Anisogametangial copulation
Isogamous copulation
88
fusion between unequal gametangia. The zygote forms a resting sporangium e.g., Aquatic fungi (Chytridiomycetes)
Anisogametangial copulation
89
two morphologically simillar gametangial hyphae come in contact, the wall at the point of contact dissolves and the contents mix in the cell thus formed; this results in the formation of zygospore e.g., Mucor, Rhizopus, Phycomyces
Isogamous copulation
90
Some fungi like rusts bear numerous minute, non- motile uninucleate
fq: male cells called __________
spermatia (sing. Spermatium)
91
Spermatia are produced in spiral receptacles called
spermagonia (sing. Spermagonium; or pycnia (sing. Pycnium)
92
no sex orgas are produced and somatic cells function as gametes
Somatogamy
93
Different Types of Sexual Spores
Ascospores
Basidiospores
Zygospore
Oospores
94
non- meiotic spores produced inside specials sacs called asci ; produced by members of ascomycota
Ascospores
95
non-motile meiospore formed on short outgrowths of club-shaped structures called basidium
Basidiospores
96
large, thick-walled spores formed at the tips of 2 sexually compatible hyphae; produced by members of Zygomycota
Zygospore
97
spores formed within a specialized female structure (oogonium) after fertilization of eggs by male gametes formed in an antheridium
Oospores
98
