kingdom fungi

kingdom fungi characteristics

• heterotrophic eukaryotes

• freshwater, marine, terrestrial habitats

• mostly multicellular

• terrestrial fungi reproduce by spores

zygospores

sexually reproduced in phylum zygomycota

zygosporangia

thick-walled resistant structure formed during sexual reproduction in zygomycete fungi

thallus

complete body of a fungus that lacks true stems, roots, leaves, or vascular tissue

heterokaryotic stage

phase in the fungal life cycle where 2 genetically distinct cell nuclei share the same cell without fusing together

what are kingdom fungi’s cell walls made of

chitin

what does the fungi structure consist of

mycelium, hyphae, fruiting body, sporangia

mycelium

vegetative (non-reproductive) body of a multicellular fungus composed of hyphae

hyphae

• threadlike filaments formed by cells joined end to end

• secretes digestive enzymes into surrounding substrate to absorb nutrients

• terminal cells produce spores

septate hyphae

separated by cell walls made of chitin

fungi species that lack septa

coenocytic

nonseptate

cell walls incomplete or lacking

fruiting body

reproductive structure formed by a spore-forming hyphae

sporangia

enlarged reproductive structures at the ends of specialized hyphae that produce spores

fungi reproduction characteristics

• spores can produced through mitosis (asexual) or meiosis (sexual)

• adults are typically haploid (n) referred as either + mycelia or - mycelia

asexual reproduction in fungi

1. reproductive hyphae produce mitospores (n) by mitotic division

2. germinate into new mycelia (n)

sexual reproduction in fungi

1. haploid mycelia in 2 opposite mating types + and - form special cells that become gametes (n) when opposite types are in contact

2. gametes + their nuclei fuse to form a diploid zygote (2n) that produces daughter cells by meiotic division

→ daughter cells may become meiospores (n) or form a sporangium that release meiospores

3. spores germinaate to form new haploid mycelia

4. plasmogamy

5. karyogamy

plasmogamy

fusion of the cytoplasm, forming dikaryotic hyphae

karyogamy

fusion of haploid nuclei

what phylums/groups are under kingdom fungi

phylum zygomycota, phylum ascomycota, phylum basidiomycota, phylum deuteromycota, lichens

phylum zygomycota characteristics

• important saprobes of decaying plants + animals

• contain 3 types of hyphae: stolon, rhizoid, sporangiophore

stolon

spread over the surface as the mycelium grows

rhizoid

penetrate the substrate to digest it + to provide anchorage

sporangiophore

upright hyphae that form a sporangium at the tips, produce spores

examples of phylum zygomycota

common black bread mold, shot gun fungus

common black bread mold

grows on rotting fruits, vegetables, soil, + animal feces

shot gun fungus

• spores propelled by hyphae (up to 2 meters) then consumers + excreted by animals

• phototrophic (turns towards the sun) to propel spores

sexual reproduction in Rhizopus

1. 2 mating types: + and -

2. zygotes develop a protective cell wall to become a zygospore (2n), resistant to unfavorable environmental conditions

→ germinates by meiosis to form a sporangiophore

phylum ascomycota characteristics

• symbiotic relationships with plant roots: improve uptake of water + minerals by plants

• tiny sacs called asci, formed by meiospores during reproduction

another name for phylum ascomycota

sac fungi

examples of phylum ascomycota

yeast, Penicillium, edible truffles + morels

importance of Penicillium

this genus was the first antibiotic

examples of sac fungi

Aspergillus, Ophiostoma, Peziza, Clavceps purpurea

Aspergillus

causes infections + allergic reactions

Ophiostoma

parasitic fungi that causes Dutch elm disease

Peziza

grow on decaying plants, animals, + dung

Clavceps purpurea

• ergot fungus, parasitizes rye + wheat grass

• causes humans to have seizures + hallucinations

• may have been a reason for salem witch trial

sexual reproduction in sac fungi

1. two opposite mating types (+ and -) touch + form multinucleated reproductive cells

2. they grow together in an ascocarp

3. asci form at the tips of the hyphae, lining the inner surface of the cup

4. the nuclei inside each ascus fuse + undergo meiosis to produce 8 ascospores

5. mature ascospores are blown away by wind currents + germinate into new hyphae

asexual reproduction in sac fungi

the fungus produces conidia on conidiospores, which are easily scattered by the wind to clone the fungus quickly

ascocarp

mycelium formed by dikaryotic hyphae, hyphae of both types develop into a cup- or sac-like shaped fruiting body that produces spores

asci

enlarged cells that form at the tips of dikaryotic hyphae + lines the inner surface of the ascocarp cup

ascospores

• formed when meiosis of fused haploid nuclei occurs resulting in 8 ascospores in each ascus, 4 or 8 of each type

• carried by air currents when mature + germinate into new hypha

reproduction in Peziza

1. haploid ascospores germinating into haploid mycelia of opposite mating types

2. plasmogamy occurs, created dikaryotic hyphae (n+n) containing two distinct nuclei per cell

3. these dikaryotic hyphae grow into an ascocarp

4. asci form along the inner surface of the cup

5. karyogamy occurs to form a single diploid nucleus (zygote, 2n)

6. the diploid nucleus undergoes meiosis to produce 4 haploid nuclei, followed immediately by mitosis to yield 8 ascospores inside each ascus

7. mature ascospores are released into the air from the top of the cup to start the cycle again

phylum basidiomycota is also known as

club fungi

phylum basidiomycota reproduction

1. dikaryotic hyphae grow to form a basidiocarp

2. the lower surface of the cap contains several gills composed of thousands of basidia

3. nuclei inside the basidia undergo sexual reproduction (karyogamy + meiosis) to produce basidiospores

4. the basidiospores are released from the gills to germinate + grow into new hyphae

examples of phylum basidiomycota

mushrooms, puffballs, shelf fungi, rusts + smuts, plant parasites

basidiospores

spores formed in sexual reproduction in phylum basidiomycota

basidia

club-shaped, terminal cells of reproductive hyphae

basidiocarp

fruiting body composed of a cap, supported by an upright stalk

stipe

stalk/stem

pileus

cap on top

gills

contain basidia which releases billions of basidiospores formed in sexual reproduction

phylum deuteromycota is also known as

imperfect fungi

what does imperfect fungi mean

lacks a sexual reproductive cycle

phylum deuteromycota characteristics

• most diverse

• causes diseases in humans

• used to make cheese

examples of phylum deuteromycota

ringworm, athlete’s food, yeast infection, roquefort, bleu

conidiospores

• erect hyphae formed when mycelium develops produce mitospores at their tip

• germinates into a new mycelium when dispersed by air currents

what are examples of mutualistic symbiotic associations involving fungi

mycorrhizae, lichen

mycorrhizae

• mutualistic relationship between a fungus + plant roots

• most are phyla zygomycota, ascomycota, + basidiomycota

1. the fungus expands the root system’s reach to help absorb water + minerals from the soil

2. the plant provides the fungus with sugars made during photosynthesis

mutualistic

both organisms are benefiting from one another

lichen

• mutualistic relationship between a fungus + a photosynthetic partner (green algae or cyanobacteria)

• most are composed of ascomycetes or basidiomycetes

1. the fungus provides structural support, protection, + retains moisture

2. the algae/cyanobacteria feed the fungus by producing organic nutrients via photosynthesis

types of lichens

crustose, foliose, fruticose

crustose

thin crust that is tightly attached to rocks

foliose

thicker with a flattened body form, most commonly occurs on rocks

fruticose

erect, often branches, body form + may occur on trees, soil, or rocks