Kingdom Fungi Flashcards
nutrition in fungi
(a) Saprophytic :- These fungi obtain their own food from dead organic matter (absorb
soluble organic matter) such as bread, rotting fruits, vegetables and dung.
(b) Parasitic :- These obtain their own food from living organism such as plants, animals
and human beings.
They obtain nutrition with the help of haustoria.
exception in cell wall composition in fungi
Cell wall is made up of chitin (fungal cellulose) and polysaccharides but Cell wall of the
members of Class-Oomycetes is mainly made up of cellulose.
how is food stored
In fungi the stored food remains in the form of glycogen and oil.
repro: vegetative propogation
(i) fragmentation
(ii) budding-saccharomyces
(iii)fission- schizosaccharomyces
Reproduction by bud formation and fission is found only in non mycelial forms.
repro:asexual reproduction
spore formation
- spores are formed by mitosis
(i) Sporangiospores
-formed endogenously in sporagium fruiting body
-sporangium is present on a fungal filament called sporangiophore
- zoospores- motile spores with flagella. In this condition the sporangia are called zoosporangia.
-aplanospores-non motile/non flagellated
(ii) conidia
conidiophore- erect fungal filament where conidia are formed
conidia are formed in a chain like manner exogenously
what is gametangium
The structure in which gametes are formed
what is synkaryon
Karyogamy - In this stage the nuclei present in the cell fuse with each other to form
a diploid nucleus which is known as synkaryon.
types of sexual repro
-gametangial contact
-gametangial copulation
-somatogamy
-spermatization
describe gametangial contact
In this process, first of all male and female sex organs are formed on two different
hypha of same mycelium. Male sex organ is called antheridium and female sex
organ is called oogonium.
In mature antheridium & oogonium both have one – one nucleus. Antheridium and
oogonium come close to each other and perform plasmogamy and karyagamy then
oospore(2n) is formed. Now meiotic division takes place in oospore(2n), as a result
of which haploid spores are formed. Now each spore germinates and gives rise to a
new mycelium.
describe gametangial contact
In this process, two identical
gametangia directly fuse to
perform plasmagamy and
karyogamy resulting in
formation of diploid zygospore.
(b) Now meiotic division takes
place in zygospore(2n), as a
result of which haploid spores
are formed. Now each spore
germinates and gives rise to a
new mycelium.
describe spermatization
Some fungi form uninucleate thin walled non motile spore like bodies. These spores are
called spermatia or Pycniospores (nonmotile male gametes).
describe somatogamy
In it sex organs are not formed only two hyphae come close to each other and their cells
get fused.
classes of phycomycetes
Oomycetes :
Asexual reproduction - By sporangiospores (Zoospores) & Conidia.
Sexual reproduction - By Gametangial contact, Oogamous.
Examples :-
(a) Phytophthora infestans - Causes “Late blight of potato”. This disease is known as
“Famine of Ireland” – 1845
(b) Albugo candida or Cystopus candidus - Albugo causes “White rust or white spots
disease” in the members of cruciferae or brassicaceae family. (Mustard)
(c) Pythium species - Causes ‘‘Damping off’’ disease in tobacco & ‘‘vegetable crops’
Zygomycetes -
Asexual reproduction - By sporangiospores (aplanospores)
Sexual reproduction - By Gametangial copulation, Isogamous
(a) Pilobolus - It grows on dung, as it is dung loving fungi therefore, it is called
coprophilous fungi.
(b) Rhizopus & Mucor - These are known as Bread mould - They prefer to grow on
bread.
explain repro in ascomycetes
Uninucleate and septate. Septa are found in mycelium of ascomycetes. Pores are
present in septum.
Asexual reproduction - by conidia
Sexual reproduction – by “Somatogamy” and “Gametangial contact”
ascospores
types of ascocarp
-cleistothecium
ball shape
-perithecium
flask shape
-apothecium
disk shape
explain ascospores
two hyphae fuse and form dikaryon
a hyphae arises from dikaryon called ascogenous hyphae, the nuclei enter into the hyphae and form ascus
the nuclei fuse in ascus and then undergo meiosis to form ascospores
minimum 4 spores in one ascus ther are generally 8 ascospores
the mycelium grows around ascus forming fruting body called ascocarp.
examples of ascomycetes
(i) Penicillium
-penicillin antibitotic
(ii) Aspergillus
aspergillioisis disease caused
apergillus niger - citric acid can be obtained
(iii) morchella
members of morchella called morel and eaten
(iv) claviceps
claviceps purpurea causes ergot’s disease in bajra and rye
lsd- (lysergic acid diethylamide) hallucinogenic drug can be obtained form it
(v) neurospora crassa
-used by beadle and tatum for research
(vi) truffles
(vii) yeast
Erysiphe :- Different species of Erysiphe causes “powdery mildew” disease on plants.
features and uses of yeast
in sugar solution it undergoes rapid multiplication and forms pseudomycelium
-used in bakeries and breweries
(saccharomyces cerevisiae)
what is the dolipore septum in basidiomycetes
One big pore is present between every
septum. The boundary of pore is spread on both
sides, this boundary is called as parenthesome.
Due to the spreading of the boundary on both
sides, the shape of septum becomes dome
shaped due to which it is called as dolipore septum.
what is clamp connection b/w cells in basidiomycetes
It is a tubular relationship between two neighbouring cells. It
the help of this connection the nucleus of one cell can migrate to the neighbouring
cell, due to which the other cell becomes dikaryotic (binucleate). Clamp connection
is used to change monokaryotic mycelium to dikaryotic mycelium in
basidiomycetes.
sexual repro in basidiomycetes
spermatization
somatogamy
explain basidospore s
to mycelium fuse to form dikaryon,
the nuclei in dikaryon are replicated and each move to the neighbouring cell via clamp connectionThis is called dikaryotisation
a club shaped structure called basidium develops on the dikaryotic cells
the nuclei moves into the basidium and fuse to form zygote
this undergoes meiosis to form basidiospores
exogenous
in which fungi spermatisatin takes place
his type of reproduction is more commonly seen in those fungi that cause rust
disease in wheat
e.g. - Rust fungi – Puccinia
Puccinia graminis - Black rust or stem rust in wheat.
Puccinia is a heteroecious fungus because it needs two hosts to complete its life
cycle.
(a) Wheat (Main host)
(b) Barberry (Alternate host)
examples of basidiomycetes
Bracket or Shelf fungi :–
(b) Puff balls –
(c) Mushrooms – These are umbrella like fungi often seen growing in grounds
during rainy season. Some mushroom are edible.
Most delicious mushroom - Agaricus bisporus
World’s most poisonous mushroom - Amanita muscaria – [It is hallucinogenic]
(Poisonous mushrooms are known as Toad - stool)
Smut fungi :– It causes smut disease on plant. Smut diseases mainly affect the
seeds of crop plants. Smut fungi infect seed and form black sooty spores inside
the seed.
eg. Ustilago nuda tritici – It causes “loose smut of wheat.” This disease spreads
by infected flowers and seeds.
Starting of rust disease (Primary infection) on wheat plants takes place through aeciospores.
