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What does it mean that fungi are mostly saprobes?
They are decomposers
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Fungi are absorptive ___________
heterotrophs
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what are the cell walls of fungi made out of?
chitin (a polysaccharide)
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what is one example of a single celled fungi?
yeast
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what type of body plan do most fungi have?
filamentous
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what is are hyphae?
long branched filaments of fungi
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what are mycelium?
tangles mass of hyphae in fungi
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why is a filamentous structure advantageous?
provides a large surface area
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what are the 2 hyphal forms?
- septate - have cross-walls
- coenocytic - no cross-walls
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how are septate hyphae organized inside?
incompletely divided into separate cell-like compartments, each compartment has pores in septa which allow movement of organelles and other materials between compartments, one nucleus in each compartment
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how are the hyphae of coenocytic mycelia organized inside?
have no separation, no septa
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how are different hyphae highly evolved?
can have parasitism, mutualism with plants, predation
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where is most of a fungus located?
underground, the visible part is just the spore-producing reproductive structure, they are connected to each other underground by the mycelium
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what is the mushroom part of the fungus?
"fruiting bodies" formed for sexual reproduction
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what is a fairy ring?
when mushrooms are arranged in a circle above ground, connected by mycelium undergound, really one large organism
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what are spores?
- unicellular reproductive structures; generated asexually or sexually
- produced by meiosis
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what is a basidium?
a mushroom gill
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what is diploid?
2 copies of each gene (2 matching chromosomes)
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what is haploid?
1 copy of each gene
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what is mitosis?
- produces 2 genetically identical daughter cells
- 1 parent cell (2n) makes 2 daughter cells (each 2n)
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what is meiosis?
- produces 4 genetically different daughter cells
- 1 parent cell (2n) makes 4 daughter cells (each n)
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how can fungi reproduce asexually?
- budding
- fission
- spores produced in sporangia
- conidia "naked spore"
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what is budding?
organism grows a part of its main body and this new growth eventually breaks off to become a new organism
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what is fission?
an organism literally splits in half, sharing important nucleic information to form a new organism
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what are conidia?
asexually produced spores that are borne externally to the cells that produce them
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what are sporangiospores?
produced inside specialized cells called sporangia and remain enclosed in the cells until maturity
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how are spores commonly dispersed?
by wind and water
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what is mycorrhiza?
- mutualistic association of fungus with plant roots
- 2 types: ecto- and endo-
- fungus receives carbs from plant
- plant receives minerals and water
- has been shown that this is actually more beneficial for the plant
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how long have plants and mycorrhizae had a partnership?
scientists have found fossils of mycorrhizae older than vascular plants
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what are lichens?
- a mutualistic relationship between a fungus and either a cyanobacterium or a unicellular green alga
- the algal or cyanobacteria part is photosynthetic, fungus protects alga by retaining water and capturing minerals
- cyanobacteria does extra thing - fix atmospheric nitrogen
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what are some special qualities that lichens have?
- break down rocks to form soil
- food for tundra animals
- "air pollution indicators" - very sensitive to toxins in air
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how many species of fungi are known?
~70,000
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what quality to animals and fungi share in the phylogenetic tree?
- flagellum, if present, is single and posterior
- closely related species
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what are synapomorphies?
traits shared by 2 or more taxa and their most recent common ancestor, whose ancestor in turn does not possess that trait
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what is the synapomorhpy that fungi have?
absorptive heterotrophy; chitin in cell walls
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what are the modes of asexual reproduction in fungi?
- production of haploid spores in sporangia
- production of haploid spores at tips of hyphae
- binary fission
- breakage of mycelium
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what is the general life cycle of fungi like?
- most life is haploid, only zygote is diploid
- "haplontic" life cycle
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what are basidiomycota?
- club fungi
- saprobes (decomposers)
- ectomycorrhizae
- rusts and smuts
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where are basidiomycota found?
terrestrial and aquatic
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what are the fruiting bodies of basidiomycota?
- basidocarps
- mushrooms, puffballs, brackets
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how many species of basidiomycota are there?
~30,000
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what are ascomycota?
sac fungi
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what are the fruiting bodies of ascomycota?
- contained in sacs (asci)
- morels, truffles are examples
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how many species of ascomycota are there?
- ~64,000
- include lichens (1/2 of species), brewer's and baker's yeasts, molds and mildews (like penicillium, aspergillus, ergotism, dutch elm disease, chestnut blight)
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how do ascomycota produce asexually?
conidia produced in specialized hyphae
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what is Geomyces destructans?
- belongs to ascomycota group of fungi
- cold-loving
- causes white-nose syndrome in the little brown bat
- 7 million bats killed so far
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what are glomeromycota?
- form arbuscular mycorrhizae (endomycorrhizae with plants, tree-like, no penetration of cell membrane)
- have no known sexual stage
- shown to increase plant's tolerance of stress and pathogens
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where are glomeromycota found?
terrestrial
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how many species of glomeromycota are there?
<200 species
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what kind of hyphae do glomeromycota have?
coenocytic hyphae
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what are zygomycota?
- type of fungi that have spores contained in sporangia atop specialized hyphae
- zygotes contain many 2n nuclei
- parasitic, saprobic
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where are zygomycota found?
terrestrial
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how many species of zygomycota are there?
>1000
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zygomycota have sporangia, but no ______
fruting bodies
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zygospore is highly resistant to _______
harsh conditions
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dikarya and glomeromycota are _______
sister groups on the phylogenetic tree
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zygomycota and the clade of glomeromycota and dikarya are __________
sister groups on the phylogenetic tree
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how many species of chytrids are there?
<1000
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chytrids are the only group that have ________ stages
flagellated
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chytrids have both _____ and _____ stages
unicellular and multicellular
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chytrids have no temporal separation between which 2 life cycle stages?
plasmogamy and karyogamy
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what is plasmogamy?
- stage in sexual reproduction of fungi
- cytoplasm of 2 parent mycella fuse together without fusion of nuclei
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what is karyogamy?
fusion of pronuclei of 2 cells
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chytrids live mainly where?
aquatic locations
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chytrids are largely responsible for _____ decline
amphibian
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what are 3 qualities that describe chytrids?
parasitic, mutualistic, saprobic
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