Fungal Taxonomic Groups

Question 1

Phylum Chytridiomycota (“Chytrid fungi”)

Answer 1

most ancestral living fungal group; mostly aquatic, also found in wet/mucky soil; ZOOSPORES & GAMETES swim using flagella!

often pathogens of plants, algae, and animals; global amphibian declines (> 500 species at risk, ~100 species extinct) are strongly linked to chytridiomycosis, disease caused by the chytrid
fungus, Batrachochytrium dendrobatidis

Question 2

Batrachochytrium dendrobatidis

Answer 2

chytrid fungus, spreads through water, infecting frogs through their skin…problem because amphibians rely on breathing through skin for respiration

Question 3

Mycorrhizal fungi

Answer 3

have mutualistic relationships with plants (multiple phyla have these fungi living with them)

Question 4

Phylum Zygomycota

Answer 4

responsible for lots of organic matter decomposition; many bread and food molds; hyphae penetrate bread/food, harvesting nutrients from bread, eventually leading to spore-producing sporangia

reproduction characterized by a ZYGOSPORANGIUM

Question 5

Zygosporangium

Answer 5

(diploid) –formed by union of gametes from
gametophyte; matures and produces haploid spores (leading to new mycelia)

Question 6

Alternation of Generations in Phylum Zygomycota

Answer 6

Haploid Stage(n): spores are released by sporangium; they land somewhere and begin to grow (using mitosis); then two hyphae meet to form zygosporangium

Dikaryon Stage(n+n): no immediate fusion of gamete spores at first, spores form in zygosporangia; gametes from two hyphae finally fuse(fertilization)

Diploid stage(2n): zygosporagium matures, produces spores

Question 7

Phylum Glomeromycota

Answer 7

major plant symbionts that are only belowground; hyphae grow into plant
roots, and GROW INTO INDIVIDUAL ROOT CELLS, known as ARBUSCULAR
MYCORRHIZAE

Question 8

Arbuscular mycorrhizae

Answer 8

contact plasma membranes of root cells; Hyphae extend
outward into the soil; Hyphae extend inward,
penetrate cell wall, and contact plasma membrane

Live off of true mutualism (+,+): plant gets nitrogen and phosphorus from fungus (which fertilizes plant, increasing growth/reproduction); fungus gets carbon from plant, used to form sugars in photosynthesis, increasing
growth/reproduction

Question 9

Phylum Ascomycota

Answer 9

known as cup/sac fungi –75% of all fungi - LARGEST GROUP!!!

NOT MUSHROOMS (they are a different group)!!!

includes truffles, yeasts, morels, Penicillin producers, pathogens
(blights/rusts), and major decomposers

Question 10

cups/sacs of Phylum Ascomycota

Answer 10

reproductive structures; lined with many reproductive, spore-producing
structures; known as ASCI (ASCUS, singular)

made of modified hyphae, lined with many individual sporangia (asci),
which are “sac-like” structures (containing 8 haploid ascospores) – once mature, spores

Question 11

Alternation of Generations in Phylum Ascomycota

Answer 11

Haploid stage(n): spores are dispersed and germinate to form hyphae

Dikaryon Stage(n+n): hyphae make contact and fuse after period of time and make a mature, spore-producing body

Diploid Stage(2n): spores produced in meiosis

Question 12

Morels

Answer 12

in phylum Ascomycota, found in forested areas around Midwest and NE US; aboveground, fruiting body portion; asci (spore-producing structures) along inside edges

Question 13

Truffles

Answer 13

in phylum ascomycota; Ascomycota associated with roots of particular tree species (they are mutualistic mycorrhizae); they are the fruiting bodies attached to belowground mycelium

give off odors that are very attractive to pigs, some dogs; use these animals to find them in forests across the
world; very expensive because they cannot be cultivated and
can only be found through specialized means (pigs/dogs), are very
sensitive to climate (don’t grow everywhere), and they are found only
during a brief interval (when they are reproducing

Question 14

Pathogens of Phylum Ascomycota

Answer 14

major agricultural pests, such as blights and mildews & ergot

Question 15

Ergot

Answer 15

pathogen/pest of phylum Ascomycota, infects grains,
causes insanity, gangrene & other problems in
humans who eat it. Ergot may have caused behaviors that led to the
Salem witch trials

Question 16

Cordyceps & Ophiocordyceps (Ascomycota) –insect pathogens

Answer 16

grows inside the organs/nervous systems of insects, eventually kills it and grows the reproductive structure out through the head

Question 17

Yeasts

Answer 17

(Ascomycota that lack asci)

the ONLY unicellular fungi, can be food & sometimes pathogenic.

Use asexual reproduction (new cells bud off existing cells)

Often COMMENSAL ORGANISMS (+,0), where fungus gets
carbon/structure and host is neither hurt nor helped.

Question 18

Saccharomyces cerevisiae

Answer 18

yeast in phylum Ascomycota which is used in making bread, beer, and wine

Question 19

Candida spp.

Answer 19

wild yeast responsible for yeast
infections, and thrush (on tongue), among other pathogenic conditions

Question 20

Penicillium

Answer 20

in phylum Ascomycota, produces antibiotic penicillin (fungus uses it as toxin to reduce competition with bacteria); lack asci

Question 21

Aspergillus

Answer 21

in phylum Ascomycota; fungus used to make miso, soy sauce, sake, lacks asci

Question 22

Lichens

Answer 22

common on rocks, trees, buildings…result of a mutualism
(+,+) between an Ascomycota and a green alga or cyanobacteria

Like other symbioses, they trade C and N/P, enhancing each other’s
growth and reproduction; produce pigments, that were used for dyes
by Irish and Scottish folks for their family tartans

Question 23

Lichens cross-section

Answer 23

Surface, where you find symbiont (green algae or cyanobacteria); Below that, a layer of hyphae, and, below that is a layer of chitin that provides structure & stability

fungi gain carbon from algae’s photosynthesis (in form of sugars),
and algae gain N/P from hyphae foraging activities

Question 24

Tolypocladium inflatum

Answer 24

ascomycete fungus (from Norwegian soil); bioprospecting found that it produced the immunosuppressant drug ciclosporin; revolutionized transplant biology for humans by creating a higher chance of acceptance of new organs to the body!

Question 25

Phylum Basidiomycota

Answer 25

mushrooms, toadstools (fruiting bodies, known as BASIDIUM); also includes smuts (like corn smut –eaten in some parts of world),
the rusts, puffballs, and “jelly fungi”

some are edible and others are poisonous(often deadly), containing aflatoxin and vomitoxin

Question 26

Fruiting bodies of Basidiomycota

Answer 26

have basidium(each have four basidiospores), made of modified
HYPHAE arising from the mycelium (the whole organism) that are
altered for reproduction to produce spores

lined with basidia(sporangia) on gills(underside of fruiting body); When mature, spores are released & spread to environment; When conditions are right (relative to soil moisture & temperature), spores will germinate,
and lead to a new mycelium

Question 27

Fairy Rings of Phylum Basidiomycota

Answer 27

an underground mycelium forms a circle as it grows
outward; result from nitrogen leaking out of hyphae at its outer edges where it is growing fastest, fertilizing the grass (making it greener)

Question 28

Mycorrhizal Basidiomycota

Answer 28

Ectomycorrhizae; form sheaths around roots and penetrate between root cells; hyphae grow AROUND cells; Plant get N,P from
fungus; fungus gets C from plants

Question 29

Ectomycoorrhizae vs Arbuscular mycorrhizae

Answer 29

Ectomycorrhizae (grow aroundcells) – Basidiomycota

Arbuscular mycorrhizae (grow into cells) – Glomeromycota