Mycology midterm 1

What is the organism that basal fungi derrived from?

Choanoflagellates

What was the first fungi on land? and in which period did the go t oland

Chytridiomycota. cambien safely possible precambien (ice cores)

What fungus came onto land in the late cambian period? after the chytridiomycota

Zygomycota,

When did the glomeromycota move to land?

Ordovician period

what was the first species to become obligate symbiots?

Glomeromycota

What was found in the late devonian period?

Ascomycota

What fungus didn’t evolve until the Carboniferous period?

Basidiomycota

describe the prototaxites

large 1m wide and 8.8m tall fungi on land in the late devonian

what similarities do choanoflagellates and fungus have in common

make chitin, choanoflagellates are similar to zoospores or sponge tissue

Explain delayed evolution theory

That when plants in became capable of producing lignin that fungus had not not developed the enzymes needed to break it down. so there’s a large period of time where almost no decomposition of plant matter occurred. disrupting the carbon cycle

what is the order in evolution of fungal groups?

Chytridiomycota, Zygomycota, Glomeromycota, Ascomycota, Basidiomycota

Define fungus

a heterotrophic organism that relies on aborbative nutrition and features a dikaryotic lifestage

what are shared characteristics between fungi and plants

cell wall (diff components) vacuole, asexual and s reproduction, spores

What are shared charcteristics between humans and fungus

glycogen for storage, heterotrophic, non photosynthetic

what is the SpitzenKorper

a unique organ for hyphael growth

what are some functions of fungal cell walls

protects from osmotic lysis, uv protection,

what is the fungal cell wall made of?

Chitin-glucan complex

what is a key differencein fungal cell membranes?

ergosterol instead of cholesterol

Main molecular difference between chitin and glucose?

a nitrogen group instead of a OH group

What is the function of b-glucans?

They are polysaccharides that are insoluble in water and help waterproof the membrane

xplain Mannoproteins

mannose sugars with protein cores, they play a role in cell shape, structural integrity, stress response, and host interaction

What are the pigments found in fungal cell walls?

melanin and cartenoids

2 fungal body forms?

unicellular or multicellular filamentous fungi

what are the 2 asexual ways that yeasts divide?

Fission and budding

what are the steps of fission

1. elongation 2. mitosis, chromosomes separate and actin ring forms in center of cell 3. during cytokenisis the contractile ring contricts and septa begins to form 4. cell cell seperation.

what is the result of yeast fission

two equal or even yeast cells

What are the steps in budding

1. an outgrowth begins on parent 2. DNA replicates and nuclei begins to migrate into bud 3. microtubule spindle forms and seperate the daughter nuclei from parent nuclei 4. cell membrane pinches inwards and seperates the daughter and parent cell.

what is a thallus?

body of mould or fleshy fungus composed of hyphae

Hyphae?

long filamentous cells joined together

How is growth in moulds conducted?

long filaments growing from the apex, the apex pushes through the substrate, the hyphae branch to form mycelium

WHat are 2 types of hyphae

aerial and vegetative

what type of spores to aerial hyphae produce

asexual

what are rhizoids?

small branching hyphae that grow downwards - function is anchorageand enzyme release

what does it mean if a fungus is dimorphic

a fungus that can exist in a hyphal multicellular and yeast unicellular form

What is an Aseptate hyphae?

long branching continous cells without septa (seperation by cross walls)

What are septate hyphae?

cells divided by cross walls (septa)

Coenocytic?

contain no septa - appear as long continous cells with many nuclei

what is a septa?

dividing wall or membrane (pores allow for cell content flow)

describe micropores?

numerous pores small enough for ribosomes, mitochondria and nuclei to pass through

What are woronin bodies

membrane-bound microbody that can plug septal pores (like drain clogs on a little string)

What are Dolipores?

barrel-shaped swelling around central pore by special membranes called parenthesomes - which allow for movement of cytoplasm

how does hyphal growth work?

vesicles produced in the golgi are brought to the tip or axis, they fuse with plasma membrane containing enzymes for lysis and wall formation.

what organ is at the tip of a growing hyphae?

Spitzenkorper

what is a rhizomorph?

complex fungal organ made by aggregation of multiple parallel hyphal with different hyphal types

What is a sclerotium

fungal myceluim that has hardened into a dormant state until environmental conditions are favourable

What is monokaryotic?

1 nucleus per hyphal compartment

Dikaryotic?

2 nuclei per hyphael compartment

DEscribe homothallic and heterothallic

homo - self fertile contains both and +
hetero - seperate * and + individuals

what are the asexual options of fungi

spores or fragmentation

How can asexual spores form from hyphae?

1. conidia (directly from hyphae)
   2. hyphae develope a multinucleated sporanguim that spores from inside

what are Arthroconidia spores?

spores formed by fragmentation

blastoconidia?

spores formed through budding hyphae

chlamydoconidia

round thick walled spores within the hyphae at the end

at what PH do fungi grow best?

5 (too acidic for most bacteria)

why can fungi grow in very low moisture?

resistant to high osmotic pressure

what is the basic respiration process used by fungi

aerobic (oxygen)

without oxygen fingu can do?

fermentation via anaerobic respiration

ethanol fermentation?

converts sugar into ATP with by-products ethanol and CO2

what is the name of bread yeasts?

saccharomyces serevisiae

what are carbon sources for fungi?

cellulose, hemi-cellulose, lignin (mostly only basidiomycota)

what is a white rot?

decomposition of lignan - cellulose left behind

brown rot

breaks down cellulose and hemicellulose - dark coloured lignan remains

In what forms can fungi get nitrogen? what form is not available to any fungi?

all can get it from amino acids
some from uptakke of ammonium
some can uptake nitrite
none can uptake nitrate

what can fungi release into soil to increase phosphate uptake

phosphatase enzymes can be released into soil to cleave phosphate from organic sources

What is the other way for fungi to access phosphates

solubilze insoluble P by release of organic acids and lowering of external PH

what is a well known fungal secondary metabolite?

penicillin - antibiotic

where does penicillin come from?

from penicillium moulds - effective against gram positive and gram negative bacteria

what is a mycotoxin?

a toxic secondary metabolite produced by fungi

What genus produces ergot?

claviceps

what grain does ergot grow on?

rye

what part of ergot tells you the plant is infected

ergot sclerotium

what are the two types of ergotism

1. Convulsions and hallucinations

2. burninf og the hands and feet due to vascocontriction

how long has humankind known about ergot

reports back to 600 BC

what major hisotorical events may have been liniked to ergot?

dancing plagues from 14th-17th centuary, tsar peter the greats campaign against the ottomans he lost his army to ergotism, the great fear pre france revolution

what are aflatoxins?

poisenous family of carcinogenic mycotoxins

what makes aflatoxins?

aspergillus

where do aspergillus grow

food crops and pet foods

what do aflatoxins cause?

immune suppression, delayed development, liver cancer, stunted growth. no cures

What is the first family of lower case f fungi we studied

OOmycota

what is a common name for oomycota

water moulds

how does Oomycota asexually reproduce

zoospores or chlamidiospores

what are the 2 types of flagella on oomycota zoospores

whiplash flagella and tinsel flagella

what are the common oomycota infections

potato blight, sudden oak death, cotton moulds.

what is the proper name of potato blight

phytothora infestans

what is the name of the genus causing sudden oak death

phytopthora ramorum

what is sudden oak death

cankers or sores appear on trees eventuall spreads to xylem and phloem, will eventually gurtle the tree

what are cotton moulds

fresh or brackish water, weird white protist infection that infects fish, common on fishfarms

what is the protist that is a parasite on fungus

phythium oligandrum

slime mould is a lower case fungi because?

its a protist, has cell wall but uses cellulose, lack dikaryotic stage, doesn’t use absorbative nutrition

what are the two forms of slime moulds?

1. cellular and plasmodial

how are slime moulds similar to fungi

they use spores, they form fruiting bodies, have cell walls

what are some components of cellular slime moulds

microscopic, aggregate when triggeres, imdividuals do ot fuse no plasmogy

in what form of reproduction is the slug formed?

asexual

example of oomycota?

phytopthora infestans - potato blight

oomycota sexual spore?

oospores

Slime mould single cell organism example

dictyostelids - model organism - used for legionella bacteria

slime mould organism example plasmomdial

dog vomit - fugilo septica

chytridiomycota organism example?

BD

skin condition caused by BD

hyperkeratosis

example organism of zygomycota

pilobolus - cow patty fungus