introduction to mycology Flashcards
describe the filamentous fungi’s general life cycle (from a fruiting body)
fruitbody releases spores (propagules)
the propagules can then germinate in the soil if favourable conditions
spores start to form hyphae in the soil
a complex network of hyphae is called mycelium
hyphae from different spores can mate with each other
some hyphae can form young mushrooms which will then become a fruiting body
NOTE: NOT ALL FILAMENTOUS FUNGI DON’T FORM FRUIT BODIES
describe the aspergillus nidulanis’ life cycle (asexual cycle, sexual cycle, parasexual cycle)
ASEXUAL CYCLE
the hyphae will have a projection form from it that can undergo asexual reproduction and distribute propagules (haploid spores) into the environment
—- in this species, the projection is called the conidiophore and the propagules are called conidium
the conidium can then germinate and form a new network of hyphae
SEXUAL CYCLE
crossing with hyphae from same organism or from another organism
the nuclei in this specific fungi has different mating types which need to mate with other mating types
the diploid then undergoes meiosis, releasing 4 spores which will then each undergo mitosis once, now with 8 spores (ascospores) in a structure called ascus which is in a cleistothecium.
the ascospores can later germinate and form their own hyphae netwrok
PARASEXUAL
no sexual structure being formed
2 hyphae come together and fuse (must be different mating types) – they lose chromosomes in this process, till they have the correct number
what are the mating types of saccharomyces cerevisiae?
a and alpha
note that yeast can switch their mating types - toggling their genetics
describe the saccharomyces cerevisiae life cycle (asexual cycle, sexual cycle)
ASEXUAL
the a mating type undergoes mitosis and makes more a yeast
alpha makes more alpha
SEXUAL
—- usually occurs when deprived of nutrients, changing their genetics to adapt
the a and alpha mating types will form schmoo cells which will fuse together to form a zygote (one of each mating type) (halpoid to diploid)
the diploid zygote can undergo asexual reproduction to form more zygotes
or it can undergo meiosis when deprived of nutrients, producing 4 daughter cells, 2 alpha and 2 a types. the spores are released into the environment
how can saccharomyces cerevisiae reproduce?
sexual and asexual
how can aspergillus nidulanis reproduce?
sexual, asexual, parasexual
how does saccharomyces cerevisiae sexually split into their daughter cells?
budding off
how does does schizo-saccharomyces pombe split into their daughter cells?
fission
how does sporulation help fungi?
dissemination, reproduction
allows fungus to move to new food source
allows fungus to survive periods of adversity
introduce new genetic combinations into a population
source of inocula for infection
when did worldwide production of mushrooms pick off? and who’s the largest producer?
around 2000s
china
how is yeast used in food production? what is used to speed up the process?
feeds on sugar, releases carbon dioxide gas and ethanol (which is evaporated when the bread bakes)
co2 is what helps bread rise
sugar and eggs speed it up
fats and salt slow it down
what is the most common yeast used in breadmaking?
saccharomyces cerevisiae
what is the most common yeast used in brewing?
saccharomyces cerevisiae us used to make ale-type beers and is known as a top-fermenting yeast
——– also used in winemaking
saccharomyces pastorianus are used to make lagers and known as bottom fermenting yeasts
for sparkling, more yeast is added when bottling
what type of fungi is used in some cheese production?
filamentous fungi
— used in blue veined cheese and soft-ripened cheese
what is mycoprotein?
protein-rich food developed from microbial biomass
produced from fusarium venatum fungus
differentiate between plant and fungal cells
plants
— cell wall = cellulose
— generally one nucleus per cell
— autotrophic
— membrane contains phytosterol
— stores food as starch in granules
fungi
— cell wall = chitin
— uninucleated or multinucleated
— heterotrophic
— membrane contains ergosterol
— stores food as glycogen in granules
differentiate between starch and glycogen
starch
— in plants
— branched or unbranched
glycogen
— in fungi
— branched
how can fungi be classified?
by their spore formation or fungal genomics
by mode of nutrition
— saprophytic: from dead organic substances
— parasitic: living organisms
— symbiotic: interdependent relationship
differentiate between lichens and mycorrhiza
symbiotic relationships between…
lichen: fungi and algae
mycorrhiza: fungi and plants
what are the types of fungal reproduction?
asexual (most common)
sexual
parasexual
describe asexual reproduction in fungi
most common
fungi that undergo asexual reproduction are referred to as anamorphs
asexual propagules are called spores, produced by mitosis
describe sexual reproduction in fungi
fungi that undergo sexual reproduction are referred to as telemorphs
sexual propagules are produced by the fission of 2 nuclei of different mating types that then undergo meiosis
describe parasexual reproduction in fung
involved genetic recombination without the requirement of specific sexual structures
what type of growth do filamentous fungi undergo?
apical!
define mycelium
network of hyphae
what is meant when a yeast is dimorphic?
can switch between a yeast phase and a hyphael phase (pseudohyphae) in response to environmental conditions
how do yeast divide?
fission
budding
