2.3 Fungi Flashcards
Fungi may seem like plants, BUT are more closely related to ______
animals
Fungi are _______
heterotrophs
Fungi are ________ [feed off of decaying matter]
saprophytes
Release _____________ into their environment and then absorb the _______
digestive enzymes; nutrients
Almost all fungi require _____ (aerobic) to carry out _________________.
oxygen; cellular respiration
true or false: rust is a type of fungi
true
2 reasons why fungi are important to our planet
They are decomposers: they recycle nutrients by breaking down organic material.
About 80% of all plants have a symbiotic relationship with fungi in which they receive essential nutrients.
Some fungi are ________: they absorb nutrients from the cells or fluids of their host, __________ it
parasitic; damaging
give examples of parasitic fungi
E.g. corn smut, rust on plants, Ringworm & Athletes foot
Fungi also produce ______________
antibiotics
True or false: Most fungi are unicellular
false
multicellular
Their bodies are made up of structures called
hyphae (s. hypha)
Hyphae
tiny threads of cytoplasm surrounded by a membrane and a cell wall
Fungi make their cell walls out of _______
chitin
what is chitin
a strong, flexible carbohydrate
where else can you find chitin?
also found on the exoskeleton of insects.
The hyphae of fungi are subdivided by additional cell walls called ____________
cross walls
The cross walls allow …
cytoplasm, nuclei and nutrients to pass throughout the hyphae to keep it alive and healthy
When hyphae grow into a large, interwoven mat, it is called a
mycelium (pl. mycelia)
In larger mushrooms, what we identify as the mushroom is called the
fruiting body
The fruiting body is an above ground extension of the ______
mycelium
the reproductive structure of fungi is _________
the fruiting body
The mycelium ______ the fungi
feeds
Because it is so fibrous, it _____________ to obtain the most amount of nutrients
maximizes surface area
The ability for the mycelium to grow up to a kilometre a day makes up for the …
inability of fungi to move to find nutrients
mycorrhizae
Fungus found on plant roots
what forms a mutualistic symbiosis with plant roots
mycorrhizae
what does mycorrhizae get from plant roots
Receives sugars, starches, proteins and lipids from the plant roots
Fungus acts like an extension of plant roots to allow it to…
absorb more nutrients
benefits of mycorrhizae having a small size
Small size allows them to penetrate areas that normal plant roots cannot
asexual reproduction
-Hyphae break off
-Spores are released:
-spores are haploid cells have tough cell walls,
and are able to survive unfavourable conditions
for long periods of time
-once favourable conditions return, then
germination can occur
-spores can spread via the wind
-eg. puffballs
Fungi have two sexes:
+ and -
sexual reproduction
-Fungi have two sexes: + and -
-Opposite haploid hyphae grow towards each other
and fuse to form a diploid zygospore with two sets
of chromosomes, one from each “parent” hyphae
-The zygospore produces haploid spores that are
genetically unique
-It will eventually grow into a large, above ground
fruiting body
-The two nuclei will eventually fuse creating a
single, diploid nucleus
-This will then divide via meiosis to create haploid
spores, and finish the cycle
In certain types of fungi (club and sac), a stage of development occurs that results in structures called ___________
dikaryotic hyphae
in which types of fungi do structures like dikaryotic hyphae result
club and sac fungi
when are dikaryotic hyphae produced?
These are produced when two nuclei are found per cell, one from each ‘parent’ hyphae.
Zygomycota are also known as …
common moulds
reproductive structure of zygomycota
Zygospores that contain sexual spores are durable
examples of zygomycota
Black bread mould, “hat thrower”
which phylum is common moulds in?
zygomycota
which phylum is club fungi in
Basidiomycota
reproductive structure of basidiomycota
Club shaped basidium contains sexual spores
examples of basidiomycota
Mushrooms, club and shelf fungi, puffballs, rusts
which phylum is sac fungi in
Ascomycota
reproductive structure of ascomycota
Contain sexual spores
examples of ascomycota
Yeasts, truffles, morels
which phylum are chytrids in
Chytridomycota
reproductive structure of chytridomycota
Only fungi with flagellated spores
examples of chytridomycota
chytrids
which phylum is the only fungi with flagellated spores
chytridomycota
Occasionally, some mushrooms grow in a
ringlike pattern, getting larger each year. The ring of mushrooms expands outward from a central point as the fungus ______________ in the
location.
exhausts the resources
What characteristics define fungi?
Fungi do not undergo photosynthesis to make their own food as plants do.
They are heterotrophic organisms that release powerful enzymes to break down organic matter into nutrients outside their bodies.
Then they absorb the nutrients from the environment.
As well, almost all fungi need to obtain oxygen from the environment
What essential services do fungi provide for
ecosystems?
Many fungi play an important ecological role as decomposers.
Like some bacteria, fungi recycle nutrients such as nitrogen and carbon by breaking down organic material.
Plants depend on fungi to recycle the nutrients in these types of matter that may otherwise be
locked away forever.
As well, about 80 percent of plants live in symbiotic
relationships with fungi in which they receive essential nutrients
How are yeasts different from other fungi?
Yeast is a single-celled fungi
What features of a mycelium make it an
efficient structure to obtain food by absorption?
-Its fibrous structure maximizes contact with the food source
-grows rapidly throughout a food source, such as decaying matter in soil.
-can grow as much as a kilometre of hyphae each day as it branches within its food
What is the purpose of hyphae?
Hyphae absorb nutrients from the environment and transport them to other parts of the thallus (fungus body)
State the function of fungal spores
With thick cell walls, spores function as the dispersal stage in the reproduction of fungi
spores
haploid cells that have a single set of chromosomes that contain genetic material
Create a flowchart that describes the
reproductive cycle of a typical fungus,
such as bread mould.
Hyphae from two different mating types fuse to
form a zygospore –> A thick wall develops around
the zygospore which allows it to survive long
periods of dormancy –> When conditions are
optimal, the zygospore germinates and a
sporangium appears –> cycle repeats
During asexual reproduction, spores are produced in the sporangium and released into the environment
Suppose you find a fungus growing rapidly on
the surface of cheese. How might you classify
this organism?
zygomycota (common moulds)
-can also withstand long periods of dry of freezing conditions
Which phyla within the fungi kingdom has a
structure most like the endospores of bacteria?
Zygospores because they contain sexual spores that are able to withstand long periods of either freezing or dry conditions, which’s very similar to the endospores of bacteria
Why do fairy ring mushrooms have this distinctive shape?
Occasionally, some mushrooms grow in a
ringlike pattern, getting larger each year. The ring of mushrooms expands outward from a central point as the fungus exhausts the resources in the
location.
function of the fruiting body
Its main purpose is to reproduce and help spread spores of a fungus so that they can colonize elsewhere and continue growing
function of mycelium
functions as a feeding structure of fungi
its fibrous structure maximizes contact with the
food source
grows rapidly throughout a food source, such as decaying matter in soil
Plant (a) has been grown in a soil mixture rich
with mycorrhizae fungi. Plant (b) has been
grown without the benefit of mycorrhizae.
Explain why there is a difference in the two
plant root systems.
the fungus acts like an extension of the plant roots, collecting essential nutrients like water and phosphorus.
-plant a is full of nutrients and is healthy but plant b hasn’t gotten any nutrients so it isn’t as healthy.
