Lab 3: Fungi Flashcards
(88 cards)
1
Q
In what form do all fungi grow?
A
hyphae
- single hypha
2
Q
what is hyphe?
A
In fungi, long narrow strand of cells which makes up the body of a fungus.
* branched, tubular, thread-like strands that give fungus a fuzzy appear
- even compact mushrooms are composed of these
3
Q
what are a group of hyphae in a fungus called?
A
mycelium
4
Q
what is mycelium?
A
the body of a fungus which is composed of many hyphae
- a group of hyphae
5
Q
are fungi mostly unicellular or multicellular?
A
mostly multicellular
6
Q
Are fungi prokaryotic or eukaryotic?
A
eukaryotic
7
Q
are fungi autotrophic or heterotrophic?
A
heterotrophic
8
Q
what are fungi known to be?
A
Major decomposers (especially plant material)
- unlike other decomposers; can degrade cellulose & lignin (major components of plant cell walls)
- make nutrients available for recycling in the ecosystem
9
Q
Why are fungi considered Saphrobes?
A
they are heterotrophic organisms that use extacellular digestion to get their energy by breaking down dead or decaying organic material (ie. secrete digestive enzymes into it and absorbing the products of digestion)
- decomposers
- breakdown larger mol. into smaller absorbable ones
10
Q
what does the suffix -mycota mean?
A
organism of the phylum fungi
11
Q
what are the 4 major phyla of fungi?
A
- Chytridiomycota
- Zygomycota
- Ascomycota
- Basidiomycota
12
Q
Do fungi have motile or non-motile reproductive cells?
A
Non-motile reproductive cells
- exception: phylum Chytridiomycota (produce flagellated gametes during sexual reproduction)
13
Q
How do members of the phylum Zygomycota, Ascomycota, & Basidiomycota reproduce sexuall?
A
Produce non-motile gametes thus:
- hyphae of 2 mating strains grow towards each other and fuse to produce a reproductive structure
- Zygomycota: fusion of hyphae — zygospore (resistant)– meiosis – spores
- Asomycota: fusion of hyphae – ascocarp (contains asci) – meiosis – spores
- Basidomycota: fusion of hyphae – basidiocarp (mushroom) – basidia on gills surface – meiosis – basidiospores
14
Q
are most fungi terrestrial or aquatic?
A
terrestrial (some aquatic)
15
Q
Do fungi contains chlorophyll?
A
NO - lack chlorophyll as they are heterotrophs
16
Q
what kind of cell wall do the dominant stages of fungi have?
A
cell wall made of Chitin
- thus they can’t ingulf their food (ie. are saphrobes that do extracell
17
Q
how did fungi evolve?
A
evolved along with plants to eploit terrestial habitats
18
Q
What are 2 ways that fungi use to live?
A
- As symbionts - live in close assocaitions with other organisms where both organims benefit (eg. with plant roots)
- As parasites (live in or on the bodies of plants or animals and benefit at their expense)
- As pathogens that cause disease
19
Q
Symbionts
A
live in associations with another organism where both organisms benefit
20
Q
Lichens
A
association of fungi with algae
- symbiont relationship of fungi with algae
21
Q
mycorrhizae
A
A mutualistic association b/w fungi of either phylum Zygomycota or the phylum Basidiomycota and the roots of plants
Fungi grows in and around the plants roots
Plant benefits:
- aids in water & mineral uptake by the plant
- provides protection to plant roots from the environment & parthogenic organisms
Fungi benefits:
- provides fungi water & nutrients from plant roots
22
Q
Why do fungi have few adaptations against dessication in dry environment?
A
- have few adaptations
- grow within their food source and use its moisture + moisture from environment (soil/leaf littter)
23
Q
What do fungi do if their environment dries out?
A
quickly produce spores which are waterproof and can remain dormant for years
24
Q
what do fungi do when moist conditions return?
A
release spores which land on a food source to germinate and grows into hyphae
25
when are fungi conspicuous?
| - easily seen
when undergoing sexual reproduction
26
what structural adaptations do fungi have in terms of their sexual structures?
elevated or exposed sexual strucutres so that the spores released can be dispersed by air currents
## Footnote
- ex. mushroom is a reproductive structure above the soil with haphae network underneath
27
How do most fungi reproduce?
**Asexual:** fragmentation of the mycellium or by production of asexual spores
**Sexual:** fusion of gametes from 2 diff. mating strains of the same species of fungus (usually involves sexual spores for dispersal)
| - gametes produced by gametangia
28
sexual vs asexual spores
Sexual spores result from the fusion of nuclei and promote genetic diversity, while asexual spores are genetically identical to the parent organism.
sexual spores: Basidiospores (e.g. mushrooms) and ascospores (e.g., sac fungi).
asexual spores: sporangiospores (e.g., Rhizopus)
Chytridiomycota: They primarily produce asexual spores called zoospores
Zygomycota: produce both sexual (zygospores) and asexual (sporangiospores) spores
Ascomycota: This phylum produces sexual spores called ascospores, often contained within sac-like structures called asci.
Basidiomycota: They primarily produce sexual spores called basidiospores, which are formed externally on structures called basidia. Basidiomycota fungi typically lack a well-defined asexual stage.
29
How are fungi divided/grouped?
1. presence or absence of cross walls (septa) in thier hyphae
2. type of seuxal reproductive structures
30
Septa
cell walls which divide the hypha into distinct cells
31
Septa are ... hypha
| which phylum?
Uninucleate
phylum: Ascomycota & Basidiomycota
| - have cell walls
32
Asepta are .... hypha
| which phylum?
Multinucleate (more than 1 independent nuclei)
Phylum: Chytridiomycota & Zygomycota
| - no cell walls; single-celled hypha
33
Characteristics of the Phylum Chytridiomycota (Chytrids)
- mostly aquatic
- aseptate; multinucleated hyphae
- most primitive
- only group that produce motile gametes for sexual reproduction
- produce motile spores
## Footnote
- septae only present at bases of reproductive strucutres and may be present in older or injured hyphae
- some may live in soil or be parasites of algae or plants
34
Allomyces
Domain: Eukaryoa
Kingdom: Fungi
Phylum: Chytridomycota
Genus: Allomyces
Common name: water mold
| - used to be classified as Blastocladiales
35
Habitat of Allomyces
small bodies of freshwater
| - found world-wide
36
Rhizoids
- specialized hyphae
- Used to attach Allomyces to its food source (decaying organic material) in the water
- Secretes digestive enzymes to break down food
## Footnote
- not seen on the wet mount as they penetrate the seed that the fungus is growing on to obtain food and usually removed when hyphae is torn off
37
what are the reproductive strucutres where meiosis occurs in Allomyces?
diploid thick-walled Sporangia (zoospores)
- found on cluster of branching hyphae that float in the water
38
Difference b/w sporangia & gametangia
sporangia = single strucutres on diploid hyphae
gametangia (n) = double strucutres on haploid hyphae
39
Haploid vs Diploid Hyphae of Allomyces
Haploid hyphae produce gametangia
* for sexual reproduction (orange male; grey female)
Diploid hyphae produce sporangia
* thin-walled = asexual reproduction
* thick-walled = sexual reproduction
40
what do the hyphae of Allomyces look like?
fine white (clear) strands growing on pieces of seeds
41
what do the gametangia reproductive structures of the Allomyces look like?
Pairs of enlarged, round cells on **haploid hyphae** called gametangia (male & female come together)
- male gametangium: light orange in color; found on the bottom
- female gametangium: gray or colorless (elongated?); found on the top
| - positions of the male & female gametangia = species-specific
## Footnote
- reversed in lab
42
what are discharge papillae?
tiny pointed opening on the gametangia through which male & female gametes are released
43
what do the sporangia look like?
Thin-walled sporangia: elongate, gray
Thick-walled sporangia: oval, reddish-brown in color
44
thin-walled sporangia
elongate, gray or colorless
- contain discharge papillae to release diploid zoospores (flagelated spores)
- asexual reproduction
| -found on diploid hyphae
45
thick-walled sporangia
resistant, oval, reddish-brown in color
- dormant under severe conditions
- undergoes meiosis to produce haploid zoospores
- sexual reproduction
| - found on diploid hyphae
46
adaptations of Allomyces
1. Feeding: specialized hyphae called **rhizoid** that attach allomyces to its food source (decaying organic material) in the water and secrete digestive enzymes to break down its food for extracellular digestion
2. Disperal: **elavated sexual structures **to help dispersal of spores by air currents + flagellated gametes to increase reporductive success
3. Protection/survival during drought: thick-walled sporangium -- formation of **zoospores **(waterproof & dormant) until conditions improve + growing within its food surce and using its moisture
47
Name 2 friends of Allomyces
1. Neocallimastix
- lives in the intestine of herbivores
- produces cellulase to break down cellulose as nutrients for host and self
2. Batrachochytrium
- water-borne
- causes fatal infectious skin disease in amphibians (frogs, salamanders)
48
Rhizopus
Domain: Eukarya
Kingdom: Fungi
Phylum: Zygomycota
Common Name: bread mold
49
Is rhizopus: aseptate or septate? uninucleate or multinucleate?
aseptate; multinucleate
50
Characteristics of phylum Zygomycota
- terrestirial fungi
- saphrotrophs, parasites, insect pathoges, myocorrhizal symbionts with plants
- multinucleate; aseptate
- reproduce sexually: fusion of gametangia produces zygosporangium (large, thick-walled cell) which contains zygospores (resistat stage)
51
Habitat of Rhizopus
bread mold that grows on any baked goods (food source)
52
Hyphae of Rhizopus
3 types:
1. stolons
2. rhozoids
3. sporangiophores
53
Stolons in Rhizopus
- hyphae that form horizontal **branching network** which **spreads Rhizopus over the surace of the food source** (eg. bread)
- produce rhizoids wherever their tips come into contact with the food source
| - not as exposed; thinner & lighter in colour; branching network on agar
54
Rhizoids in Rhizopus
- short, branched hyphae that penetrate the surface of the bread **anchoring** rhizopus into its food source
- **secretes amylase** (digestive enzyme) which breaks down large starch molecules of bread into smaller sugar molecules taken into fungi through the rhizoid (**extracellular digestion**) -- **absorb nutrients**
| - short, branched, grow downwards towards agar
55
Sporangiophores in Rhizopus
- elongate upright hyphae directly above the rhizoids produced by the stolons during asexual reproduction
- each one bears a single globular sporangium at its tip (reproductive structure)
Adaptation of elongate sporangiophor: elevates sporangium above food source; exposes spores to air currents for dispersal
| - aerial structures; tougher; darkly pigmented; grow upwards
56
what is the reproductive structure where meiosis occurs in the Rhizopus?
sporangium (found on the tip of the sporangiophore)
- produces numeous spores through mitosis (asexually)
57
what do the hyphae of Rhizopus look like?
thin white branching strands
- contain many haploid nuclei
58
why does the mature sporangia appear black?
it contains many spores
59
how are spores produced in Rhizopus?
asexual reproduction
60
Zygospore of Rhizopus are...
Zygospores:
- aerial, dry, & very light so can travel long distances by air currents
- develops a very thick, black or brown wall to protect itself from drying out
- resistant state
- restoration of good conditions: diploid nucleus inside zygospore undergoes meiosis --- produces haploid spores
61
how do Rhizopus reproduce in times of stress (ex. dry conditions or lack of food)?
Sexual Conjugation: 2 diff strains
- each produces short side branches of haploid hyphae
- becomes haploid gametangia
- fusion of 2 gametangia
- diploid zygosporangium
- produces a single diploid zygospore
- when good conditions are restores: diploid nucleus within zygospore undergoes meiosis
- produces haploid spores
- grow into haploid hyphae
## Footnote
2 diff strains --> short side branches from haploid hyphae --> haploid gametangia --> fusion --> diploid zygosporangium --> diploid zygospore --> meiosis halpid spore --> haploid hyphae
62
what are the 4 stages of sexual conjugation in Rhizopus?
1) short side branches
2) gametangia
3) zygote
4) zygospore
## Footnote
2 diff strains --> short side branches from haploid hyphae --> haploid gametangia --> fusion --> diploid zygosporangium --> diploid zygospore --> meiosis halpid spore --> haploid hyphae
63
columella
specialized structure found within the sporangium
- provide structural support to the sporangium, helping it maintain its shape and integrity
- aid in the dispersal of spores by influencing airflow within the sporangium cavity
64
how does Rhizopus reproduce asexually?
stolon's produce sporangiophores above rhizoid, each bearing a single sporangium: **spores are produces asexually within the sporangium through mitosis**
65
what are the 5 adaptations within Rhizopus?
1. Stolon: spreads fungus over its food source (greates access)
2. Rhizoids: anchoring food source + secrete amalase to breakdown starch into absorbable sugars
3. Elongate Sporangiospores: elevates sporangium above food source; exposes spores to air currents for dispersal
4. spores: arial; lightweight & dry to travel long distance
5. zygospore: creates a thick wall to prevent dessication + protects gametes till prime condition
66
name 2 friends of Rhizopus
1. Phycomyces: produce black zygospores where 2 strains of their hyphae meet
2. Entomophthora: insect pathogen; green-stained hyphae; pushes hyphae out b/w segments of fly's body wall to produce spores to be released into th air
67
Sordaria
Domain: Eukarya
Kingdom: Fungi
Phylum: Ascomycota
Common Name: plant sprobe
68
Characteristics of phylum Ascomycota
- largest of the fungal phyla
- cup fungi, powdery mildew, yeast, morels, & truffles
- most are terresterial saprotrops
- some are plant pathogens (ergot of wheat of rye; dutch elm disease)
- septae; uninucleate (haploid nucleus)
- most reproduce asexually by producing spores
- phylum name derived from sac
69
ascocarp
a reproductive structure of Ascomycota - produces asci & ascospores
- formed during sexual reproduction when haploid hyphae of 2 mating strains come into contact
| - brown, flask-shaped in sordaria
- found around edge of plate
70
what are the sexual reproductive strucutres where meiosis occurs in the phylum Ascomycota?
Ascus; plural asci
- sac-like strucutre
71
ascus (plural asci)
**sac-like** structure within which meiosis occurs to produce haploid ascospores in fungi of the phylum Ascomycota
| - elongate; within the ascocarp
72
ascospore
a reproductive cell produced within an ascus by meiosis
| - haploid, tan colored, oval
73
habitat of Sordaria
lives as a fairly loose mycelium on **dung & decaying plant matter**
74
how do Sordaria reproduce?
- asexual reproduction is rare
Sexual reproduction:
- fusion of haploid hyphae produces brown ascocarps
75
Adaptations found in the Sordaria
1. The neck of the flask-shaped ascocarp grows towards light, guiding ascospores through gaps in surrounding vegetation--- ensures that upon release, ascospores land on fresh vegetation, aiding ingestion and dispersal by herbivores.
2. Mature ascospores are forcefully ejected from the ascus through a pore at the ascocarp's tip, traveling up to 60 mm away --- ensures spores land on living plants aiding in dispersal.
3. ascospores are coated with a sticky, gelatinous material -- allows spores to adhere to the vegetation
4. Grow within their food source and produce spores when environment dries out
76
Name friends of Soradaria
1. **Morels (Morchella):** the ascocarps of subterranean fungus; NOT mushrooms
2. **Calviceps:** causes ergot infection of grains (rye) -- form dormant, poisonous **sclerotia** in winter -- looks like long black kernels within the head of rye
- poisonous to animals & humans causing insanity, convolsions, cardiovascular colapse, fatal
- causes St. Antony's Fire disease + factor in Salem withc trials
3. Ophistoma: cause dutch Elm disease
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Agaricus bisporus
Domain: Eukarya
Kingdom: Fungi
Phylum: **Basidiomycota**
Genus: **Agaricus**
Species: bisporus
Common Name: mushroom
78
characteristics of phylum Basidiomycota
- large conspicuous fungi
- found in fields & woods
- mushrooms, puffballs, bracket fungi
- mainly terrestrial saprotrophs
- some are plant parasites
- Have SEPTA; uninucleate (haploid nucleus of hyphae)
- asexual reproduction = less common
79
what is the phylum Basidomycota characterized by?
production of basdiospores by reproductive cells called basidia (single: basidium) on reproductive strucutres called basidiocarp (eg. mushroom)
80
basidiocarp
a reproductive structure (eg. mushroom) which produces basidiospores usually on the surface of its gills
- composed of tightly packed hyphae
81
basidium
| single: basidia
a cell on a basidiocarp within which meiosis occurs to prouce basiospores (eg. cells on the surface of the gills of mushrooms)
82
basidospores
a reproductive cell produced by meiosis within a basidium
83
gill
thin structures on the underside of a mushroom cap which produce spores
- dark-brown colored seen in a longitudinal section
84
velum
tissue on the underside of a mushroom cap which **encloses and protects the basidia on the gills until they are mature & ready to release spores**
- joins the edge of the cap to the stalk
- breaks open as cap increases in size so spores produced by basidia on the gills can be released
| - only in immature mushroom
85
structure of Agaricus bisporus
- vast network of haploid septate branching hyphae burried underground within soil (food source) -- basidiospores germinate and grow into haploid hyphae -- mycelium underneat the soil
- only basidiocarp (reproductive strucutre; mushroom) is visible above ground
86
adaptations of the Agaricus bisporus
1. **Lives withn the food source** (soil) to protect body of fungus from drying out
2. Reproductive structures (basidiocarp) **above ground** to facilitate spore dispersal into air
3. Hyphae release **enzymes from hyphae** to breakdown decaying plant material in the soil & absorb available nutrients
4. Basidiospores are discharged horizontally off basidia; **short distance** guiding them between gills without landing on neighboring ones. From there, they fall from the mushroom cap, dispersed by air currents
5. protective **velum** layer covers basidia on the gills until they are mature
87
How does Agaricus bisporus reproduce?
Sexually:
2 haploid mating strains come into contact beneath the soil -- fuse -- basidiocarp (mushroom; reproductive strucutre) --- gills line underside of the cap -- basidia cells line the gills --- meiosis occurs within each basidum -- produces haploid nuclei ---- dev. into basidiospores -- fall out of gill and dispersed by air current -- germinate -- haploid hyphae -- mycelium
| basidiocarp -- gills -- basidia -- meiosis -- basidiospores
88
Name some friends of Agaricus bisporus
1. oyster mushroom
2. shiitake mushroom: darker brown cap & orange/yellow gills
3. bracket fungi: looks like a log/stump
4. puffballs: grow in rotting log, release spores as they are dit by drops of rain
