Fungi Flashcards
hypha
a tube or filament in a fungus
mycelium
a (usually) visible mass of hyphae
fungi are
multicellular
eukaryotic
heterotrophic
the body is called
a mycelium and is made up of a tangled mass of microscopic threads called hyphae
fungi cell walls are made of
chitin
why are fungi heterotrophic
no chlorophyll
fungi reproduce by means of..
spores
heterotrophic fungi (2 types)
parasitic
saprophytic
parasitic fungi
feeds off a living host (eg:) potato blight/ athletes foot
obligate parasite
can only take its food from a LIVE host
facultative parasite
can get it’s food from a live or dead host
saprophytic fungi
feeds on dead organic matter (eg:) rhizopus and yeast
is rhizopus saprophytic or parasitic
saprophytic
is yeast saprophytic or parastitic
saprophytic
are mushrooms saprophytic or parasitic
saprophytic
edible fungi
standard field mushroom
morels
truffle
poisonous fungi
death cap mushroom
destroying angel
(liver failure)
negative economic impact of fungi
food spoilage
crop diseases (potato blight)
timber rot
positive economic impact of fungi
used in baking industry to make bread
used in brewing industry to make alcohol
food source
antibiotics
structure of rhizopus (draw)
sporangium
spores
sporangiophore
stolon
rhizoid
hypha
mycelium
rhizoid function
secretes enzymes that digest the bread, absorbs the products of digestion
anchors the fungus
sporulation definition
the process of making spores
rhizopus - asexual reproduction
hyphae grow up from surface of substrate, these are called sporangiophores.
tip swells to produce a sporangium, whose contents divide by mitosis to form spores (each spore has a haploid nucleus)
in dry conditions the black sporangium dries out and opens to release many spores — blows away and grows into a new hyphae and mycelium,, if on suitable substrate
rhizopus - sexual reproduction
usually triggered by environmental stimulus like dehydration
- can only occur between a puls and minus strain
- hyphae from opposite strains grow close together, swellings grow and touch each other
- nuclei from both hyphae move into the swellings (now called progametamgia)
- cross walls form to form gametangia
- walls of the gametangia dissolve and a number of fertilisations take place producing a diploid zygote nuclei
- zygospore forms around nuclei
- when conditions are suitable the zygospore germinates by MEIOSIS
- hypha grows out of the zygospore and produces a sporangium at the tip.
- sporangium opens releasing many haploid spores which grow into new individuals.
advantages of zygospore formation
avoids harsh adverse conditions eg: drought
dispersal
yeast structure
cell wall
nucleus
cytoplasm
vacuole
food vacuole
no chloroplast no cell membrane
equation for the reaction using yeast
glucose —> 2 ethanol + 2 CO2
yeast cell wall is made of
chitin
yeast are multi or uni
unicellular
yeast respire…
anaerobically
reproduction is yeast is called
budding
budding steps
- parent yeast cell
- bud forms
- nucleus divides by mitosis
- a nucleus moves into the bud
- bud pinches off and separated from cell
if the bud doesn’t seperate
a yeast colony forms
advantage of budding
can be quick
disadvantage of budding
genetically identical
aseptic / asepsis
means that measures are taken to exclude unwanted micro-organisms
sterile
means all micro organisms are destroyed (nothing living)
aseptic techniques
wash hands
wash bench with disinfectant before and after
sterile techniques
sterilise equipment by flaming it
immerse all equipment in sterilising fluid after
experiment: the growth of leaf yeast using agar plates
- cut small branch containing leaves
- wash hands, bench etc
- flame equipment
- two sterile petri dishes containing prepped sterile nutrient agar.
- use foreceps to pick up leaf
- place vasaline on inside of lid of petri dish
- attach leaf (dark side down) and close lid
- after 24h turn it upside down (prevent condensation)
- leave dishes at room temperature for 3-4 days
- Control is and empty agar dish (no growth)
result of experiment
pink colonies form on agar
how could growth of leaf yeast be inhibited?
by air pollution
stolon hypha function
grows over the surface of the food and allows new mycelium to develop
sporangiophore hypha function
supports sporangium and allows spores to be more easily dispersed
sporangium function
produces and releases the haploid spores
columella function
separates the spores from the sporangiophore and plays a role in spore release
experiment questions: what plant did you use
ash tree leaf
experiment questions: what were the results
pink colonies on experiment plate
no colonies on control
experiment questions: what control did you use?
am agar plate with no leaf
experiment questions: why were the agar plates left 24 hours upright before turning them upside down, why?
to allow the leaf yeast to fall onto the plate
experiment questions: what is meant by aseptic conditions?
taking steps to exclude unwanted pathogenic micro organisms
experiment questions: how did you ensure the leaf was the only source of yeast
used sterile agar plates
unopened dish as a control
experiment questions: why did you seal the plates before incubation
prevent possible contamination
prevent the spread of micro organisms
experiment questions: how were the plates disposed of at the end of the experiment
autoclaved
soaked in disinfectant
experiment questions: how did you introduce the leaf yeast to the agar plates?
using aseptic technique the leaf was attached to the lid of the petri dish, under surface facing down, using vasaline
experiment questions:how did you identify the leaf yeast?
pink colonies appeared
