Fungi Flashcards
What kind of feeding mechanism do fungi use
heterotrophs, absorb nutrients from outside their body
How do fungi feed
use enzymes to break down a large variety of complex molecules into smaller organic compounds
what enzymes are excreted
oxidases, cellulases, phosphatages, proteases
what does oxidases break down
Lignin
what does cellulases break down
carbohydrates
what does phosphates break down
phosphates
what does proteases break down
proteins
Human uses of fungal enzymes
Efects of climate change
Beer production
wastewater treatment
Paper production
What do hyphae do
can act as nooses, nets, or sticky traps
Penetrate victims
what are the most common body structures
multicellular filaments and single cells
multicellular filaments
hyphae
single cells
yeasts
mycelia
networks of branched hyphae adapted for absorption
hyphae
string of cells
what are fungi cell walls made of
chitin
some fungi have hyphae divided into cells by____
septa
what is the advantages of septa
having pores that allow for cell-to-cell movement of organelles
Mycorrhizae
mutually beneficial relationships between fungi and plant roots
Ectomycorrhizal fungi
form sheaths of hyphae over a root and also grow into the extracellular spaces of the root cortex
Arbuscular mycorrhizal fungi
extend hyphae through the cell walls of root cells and into tubes formed by invagination of the root cell membrane
haustoria
specialized hyphae that allow the fungi to penetrate the tissues of their hose
Mutualistic dynamics between plant and fungus
fungus gains access to carbohydrates
plant gains an increased ability to uptake water and minerals
How do fungus reproduce
producing vast numbers of spores, either sexually or asexually
What ploidy are fungal nuclei usually
haploid
what is the exception for fungal nuclei
transient diploid stages formed during the sexual life cycles
Sexual reproduction requires the fusion of ___ from different mating types
hyphae
Pheromones
fungi use, to communicate their mating type
Plasmogamy
the union of to parent mycelia
heterokaryon
the haploid nuclei from each parent do not fuse right away’ they coexist in the mycelium, called a heterokaryon.
Dikaryotic
when the haploid nuclei pair off two to a cell, the mycelium is said to be dikaryotic
Karyogamy
nuclear fusion
may take hours, days, or even centuries
What happens during karyogamy
the haploid nuclei fuse, producing diploid cells
What happens after the short lived diploid stage
It undergoes meiosis, producing haploid spores
Molds
produce haploid spores by mitosis and form visible mycelia
Yeasts
reproduce asexually by single cell division and the pinching of “bud cells” from a parent cell
Microsporidia
Obligate, intracellular animal parasites
What do microsporidia lack
mitochondria
do not undergo aerobic respiration
Chytrids
aquatic and found in freshwater and terrestrial habitats
what kind of fungus are chytrids
can be decomposers, parasites, or mutualists
zoospores
flagellated spores in chytrids
What is in microsporidia
chytrids
batrachochytrium dendrobatidis
chytrid infects thousands of amphibians thickens the skin drives populations to extinction The spread has been linked to climate change
Blastocladiomycetes
Unglagellated zoospores
Allomyces
a Blastocladiomycetes
water mold
haplodiplontic life cycle
female gametes secrete pheromone to attract male gametes
Neocallimastigomycota
digest plant biomass in mammalian herbivore rumens
Greatly reduced mitochondria lack cristae
Zoospores have multiple flagella
horizontal gene transfer Brought cellulase gene from bacteria into Neocallimastix genome
How do neocallimastigomycota help animals
Digest plant biomass in mammalian herbivore rumens
mammal depends on fungi for sufficient calories
Zygomycota
Include common bread molds
Not monophyletic
A few human pathogens
Pilobolus
Grows on the excrement of herbivores
sporangium forms on the top of the stalk of a fruiting body
shoots spores toward the light
Glomeromycota
tiny group of fungi
Form intracellular associations with plant roots called arbuscular mycorrhizawb
Cannot survive in absence of host plant
what do basidomycetes contain
include mushrooms, puffballs, and shelf fungi, mutualists, and plant parasites
How is Basidomycetes defined
a clublike structure called a basidium, a transient diploid stage in the life cycle
What is another name for basidiomycetes
club fungi
basidiocarps
elaborate fruiting bodies that are produced sexually in response to environmental stimuli
What is an example of basidiocarps
mushrooms
where do Ascomycetes live
marine, freshwater, and terrestrial habitats
How is Ascomycetes defined
by the production of sexual spores in saclike ascidians, usually contained in fruiting bodies called ascocarps
Common name for ascomycetes
sac fungi
How do ascomycetes reproduce
asexually by enormous numbers of asexual spores called conidia
can also reproduce sexually
Example of Ascomycetes
Ergot
infects grasses
rye is susceptibe
causes ergotism
Ergotism
burning sensation lead to name, Saint Anthony’s fire
Yeast
single-celled ascomycetes
How do yeast reproduce
asexually by fission or budding
What can yeasts do
break down carbohydrates
break down glucose into ethanol and CO2
Used to make bread, beer, wine
Endophytes
live inside leaves or other plant parts, make toxins that deter herbivores and defend against pathogens
Fungus-animal symbiosis
some fungi help break down plant material in the guts of cows and other grazing animals
Lichen
a symbiotic association between a photosynthetic microorganism and a fungus in which millions of photosynthetic cells are held in a mass of fungal hyphae
what is the fungal component of a lichen
most often an ascomycete, but can also be a basidomycete
what occupies the inner layer below the lichen surface
Algae or cyanobacteria
What does the algae provide in a lichen
carbon compounds
what does cyanobacteria provide in a lichen
organic nitrogen
what does fungi provide in a lichen
the environment for growth
What are the forms of lichens
Fruticose (shrublike)
Foliose (Leaf-like)
Crustose (crust-like)
How do humans use lichens
used as dyes
used in perfumes and incense
indicator species
Mycoses
the general term for a fungal infection in animals
Candida
Human pathogen
common name is thrush
affects immunocompromised
30% or more of systemic infections are fatal
Aspergillus
Human pathogen
found on cereals and nuts
produces aflatoxins
Toxin and carcinogen
Cryptococcus
Human pathogen
cause of meningitis in immunocompromised
Penicillium
ascomycete
antibiotic for bacterial infections
