Exam 3 Flashcards
what is the difference between mycosis mycotoxins and allergens?
mycosis- fungal infections/diseases that damages tissues or skin
mycotoxins- toxic substances produced by certain molds that can cause health problems when ingested, inhaled, or absorbed through the skin
allergens- substances that can trigger an allergic reaction in the body. some molds will trigger allergic reactions such as sneezing, runny nose, and itchy eyes.
how do you prevent the spread of fungi in agriculture? who is in charge of overseeing this in the US?
-Proper handling and storage
-Low humidity
-Sanitation
the (USDA, FDA, EPA) identify and enforce maximum thresholds for allowable mycotoxins in our food
how long have we known about the harm mycotoxins can do? what are examples?
since 1932 in soviet Russia when T-2 produced by Fusarium sporotrichoides spread and killed thousands of people through contaminated bread and hay.
-mycotoxins have been used in biological warfare throughout history.
what are the three categories of mycoses and do they differ from each other? (ranges in severity)
-Superficial
on the skin; can cause dermatitis, dandruff, etc.
-Subcutaneous
cause ringworm
species within the Candidia genus causes
thrush
armpit rashes
candidiasis
-Systemic (true pathogen or opportunistic)
internal; infection starts in the lungs from inhalation of spores and spreads throughout the body
in what ways are immunocompromised people more at risk of fungal infections?
susceptible to systematic opportunistic fungal infections from blastomycosis, which is the inhalation of spores from nearby rivers and lakes. 2 in every 100,000 people obtain this infection.
what is psilocybin and how does it affect the brain?
Psilocybin is a secondary metabolite produced by over a
hundred species in the Psilocybe genus (Basidiomycota).
-psilocybin interacts with serotonin receptors in the nervous system
-usage results in hallucinations, synesthesia, reduction in anxiety, etc.
what is the legal status of psychedelics in the US?
psychedelics are illegal in the US however ceremonial usage by native americans is protected under law
what are the different biological reactions between two or more individuals?
Mutualism
Parasitism
Commensalism
Amensalism
what are the two kinds of competition? what are the two kinds of competition for fungi?
+Interference
+Exploitation
between fungi, it is
+ Primary resource capture
+ Secondary resource capture
what determines primary resource capture?
+ Good dispersal
+ Rapid spore germination and growth
+ Ability to use the resource
how do fungi combat other fungi and microbes?
+ From a distance (no contact)
+ Contact at the hyphal level
+ Large parts of the mycelia meet other mycelia
how do fungi antagonize each other from a distance?
+ Volatile chemicals
+ Diffusible chemicals
+ Enzymes
+ Toxins
+ Altering the pH of the environment
parasitism of one fungus by another
mycoparasitism?
what kinds of biotrophic parasites exist?
+ Intracellular
+ Haustoria-producing
+ fusion
form appressorium on the surface of the host and then form a peg which penetrates the host hypha.
haustoria biotrophs
how do fungi and bacteria interact? why do they compete with one another?
some fungi eat bacteria (bacterivores); bacteria can be a good source of nitrogen
+bacteria and fungi often compete for the same resources
in the soil, typically simple carbon compounds (aka sugars).
what evolutionary traits have fungi and bacteria developed to outcompete each other?
+Fungi have developed several antibacterial enzymes in
order to outcompete bacteria.
+ Bacteria have developed inhibitory metabolites which
cause mycostasis – whereby the majority of fungal spores
that land on the soil do not germinate
in what ways do viruses interact with fungi?
termed ‘mycoviruses’, these viruses usually contain a double stranded RNA which they release into the hyphal cells, may influencing their phenotype and potentially their virulence.
what are the three interconnected subsystems of an ecosystem?
autotrophs, heterotrophs, and decomposers
the exchanges between fungi and plant primary productivity
mutualistic relationship through mycorrhizae
+the fungus helps the plant obtain nutrients and water from the soil
+the plant provides the fungus with sugars produced through photosynthesis, influencing primary productivity
why is the distribution and history of fungi difficult?
because they spend most of their life cycle underground and are difficult to track
a geologic unit of time defined by human actions and how they have affected earth’s systems.
anthropocene
what categories do we use to measure impacts on ecosystems?
land use
climate change
biotic exchange
atmospheric co2
nitrogen deposition
what is happening to fungi in the face of climate change?
changes in humidity, temperature, and CO2 will alter the fungal lifecycle
+ the average time span of mushroom production has
nearly doubled
all the different types of fungi and how they are changing
+ as the planet heats up and cools plants tend to migrate, and mycorrhizal fungi has followed this migration
+ several cold temperature lichens have gone extinct while warm temperature lichens have the potential to proliferate.
as we change the land, how is fungi adjusting?
+ the diversity of all biota decreases, fungi included.
+ fertilizers, fungicides, and other farming practices can
also impact diversity and distribution of fungi
what are three classifications of pollution?
Primary
-directly emitted from a source
Secondary
- when primary pollutants react in the atmosphere, often with sunlight, water vapor, or other primary pollutants
Other
-water pollution, noise pollution, soil pollution etc.
how do lichen measure pollution?
toxic metals are more tightly bound in lichen; they
collect over long periods of time and can be used to measure pollution.
+ lichen collect radionuclides (radioactive) and can be
used to measure radioactivity in places like Chernobyl
what is the IUCN red list?
a list of threatened species consisting of plants, animals, and fungi
what are some principles we can act upon to conserve biodiversity?
maintain habitat diversity, maintain host diversity, and maintain soil health
in what ways have humans used fungi before modern technology? has that interaction altered fungal species?
+ Baking
+ Food production
+ Fermentation
+ Pharmacology
we have already started altering the natural
genetic composition of some species
what species of fungi do we farm?
shiitake mushrooms and white button mushrooms
how do we cultivate those farmed species?
they are raised on plugs of wood or on mixtures of sawdust, cereal bran and other ingredients
-once those are colonized, the spawn is pressed into holes drilled into hardwood logs and covered with bags to maintain moisture level
for what other purposes do we cultivate fungi?
beyond food, fungi can also be used as medicine
how do we use lichens?
lichen have been used for everything from dyes to embalming to perfume
understand fermentation processes
ascomycetes consume sugar and produce carbon dioxide and ethanol through a process called fermentation
what is plasmid? how do we use them in biotechnology?
small DNA molecules that replicate independently from chromosomal DNA
the plasmids used for transforming fungi originated in bacteria, they aid in protein production
how do we use fungi in meat substitutes?
protein rich foods produced from yeast, also called mycoprotein
how do we use fungi in biofuels?
fungi is used in the production/fermentation of
biotethanol
why is reducing meat consumption good for the environment?
can alleviate deforestation and lower greenhouse gas emission
how do we use fungi in medicine?
certain species can aid in lowering cholesterol, neutralizing bacteria, and supporting patients after transplants
how do we use fungi in bioremediation?
white rot fungi can help breakdown pesticides
both species are positively affected
mutualism
one is positively affected as the result of damage to another
parasitism
one is positively affected while the other is unaffected
commensalism
one is negatively affected while the other is unaffected
amensalism
resource has not previously been colonized
primary resource capture
aggressive antagonistic interactions are necessary to
capture occupied territory or defend it
secondary resource capture
how long has mycoparasitism been happening?
not sure exactly but we have some clues
+ Oldest know agaric (fruiting body) fossil not only had mycoparasites but also hypermycoparasites
produce specialized hyphae or buffer cells which work their
way through the cell wall of the host. Once the cell wall has
been penetrated, the cytoplasm from the mycoparasite fuses with cytoplasm of the host.
fusion biotrophs
an example of an intracellular biotroph
powdery mildew
what can bacteria not break down that fungi can?
(bacteria wait for fungi to break these down before swooping in and absorbing them.)
lignin or cellulose
organisms cannot produce their own food and must consume other organisms for energy and nutrients
humans, dogs, cats etc.
heterotrophic subsystem
organisms in an ecosystem that break down dead plants and animals, recycling essential nutrients back into the environment
fungi, bacteria, invertebrates etc.
decomposers
organisms capable of producing their own food from inorganic materials, primarily using sunlight through photosynthesis or chemical energy through chemosynthesis
plant, lichens, algae etc.
autotrophic subsystem
