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What does it mean that fungi are mostly saprobes?
They are decomposers
Fungi are absorptive ___________
what are the cell walls of fungi made out of?
chitin (a polysaccharide)
what is one example of a single celled fungi?
what type of body plan do most fungi have?
what is are hyphae?
long branched filaments of fungi
what are mycelium?
tangles mass of hyphae in fungi
why is a filamentous structure advantageous?
provides a large surface area
what are the 2 hyphal forms?
- septate - have cross-walls
- coenocytic - no cross-walls
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
how are the hyphae of coenocytic mycelia organized inside?
have no separation, no septa
how are different hyphae highly evolved?
can have parasitism, mutualism with plants, predation
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
what is the mushroom part of the fungus?
"fruiting bodies" formed for sexual reproduction
what is a fairy ring?
when mushrooms are arranged in a circle above ground, connected by mycelium undergound, really one large organism
what are spores?
- unicellular reproductive structures; generated asexually or sexually
- produced by meiosis
what is a basidium?
a mushroom gill
what is diploid?
2 copies of each gene (2 matching chromosomes)
what is haploid?
1 copy of each gene
what is mitosis?
- produces 2 genetically identical daughter cells
- 1 parent cell (2n) makes 2 daughter cells (each 2n)
what is meiosis?
- produces 4 genetically different daughter cells
- 1 parent cell (2n) makes 4 daughter cells (each n)
how can fungi reproduce asexually?
- spores produced in sporangia
- conidia "naked spore"
what is budding?
organism grows a part of its main body and this new growth eventually breaks off to become a new organism
what is fission?
an organism literally splits in half, sharing important nucleic information to form a new organism
what are conidia?
asexually produced spores that are borne externally to the cells that produce them
what are sporangiospores?
produced inside specialized cells called sporangia and remain enclosed in the cells until maturity
how are spores commonly dispersed?
by wind and water
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
how long have plants and mycorrhizae had a partnership?
scientists have found fossils of mycorrhizae older than vascular plants
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
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
how many species of fungi are known?
what quality to animals and fungi share in the phylogenetic tree?
- flagellum, if present, is single and posterior
- closely related species
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
what is the synapomorhpy that fungi have?
absorptive heterotrophy; chitin in cell walls
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
what is the general life cycle of fungi like?
- most life is haploid, only zygote is diploid
- "haplontic" life cycle
what are basidiomycota?
- club fungi
- saprobes (decomposers)
- rusts and smuts
where are basidiomycota found?
terrestrial and aquatic
what are the fruiting bodies of basidiomycota?
- mushrooms, puffballs, brackets
how many species of basidiomycota are there?
what are ascomycota?
what are the fruiting bodies of ascomycota?
- contained in sacs (asci)
- morels, truffles are examples
how many species of ascomycota are there?
- include lichens (1/2 of species), brewer's and baker's yeasts, molds and mildews (like penicillium, aspergillus, ergotism, dutch elm disease, chestnut blight)
how do ascomycota produce asexually?
conidia produced in specialized hyphae
what is Geomyces destructans?
- belongs to ascomycota group of fungi
- causes white-nose syndrome in the little brown bat
- 7 million bats killed so far
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
where are glomeromycota found?
how many species of glomeromycota are there?
what kind of hyphae do glomeromycota have?
what are zygomycota?
- type of fungi that have spores contained in sporangia atop specialized hyphae
- zygotes contain many 2n nuclei
- parasitic, saprobic
where are zygomycota found?
how many species of zygomycota are there?
zygomycota have sporangia, but no ______
zygospore is highly resistant to _______
dikarya and glomeromycota are _______
sister groups on the phylogenetic tree
zygomycota and the clade of glomeromycota and dikarya are __________
sister groups on the phylogenetic tree
how many species of chytrids are there?
chytrids are the only group that have ________ stages
chytrids have both _____ and _____ stages
unicellular and multicellular
chytrids have no temporal separation between which 2 life cycle stages?
plasmogamy and karyogamy
what is plasmogamy?
- stage in sexual reproduction of fungi
- cytoplasm of 2 parent mycella fuse together without fusion of nuclei
what is karyogamy?
fusion of pronuclei of 2 cells
chytrids live mainly where?
chytrids are largely responsible for _____ decline
what are 3 qualities that describe chytrids?
parasitic, mutualistic, saprobic