Kingdom Fungi

Question 1

nutrition in fungi

Answer 1

(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.

Question 2

exception in cell wall composition in fungi

Answer 2

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.

Question 3

how is food stored

Answer 3

In fungi the stored food remains in the form of glycogen and oil.

Question 4

repro: vegetative propogation

Answer 4

(i) fragmentation

(ii) budding-saccharomyces

(iii)fission- schizosaccharomyces

Reproduction by bud formation and fission is found only in non mycelial forms.

Question 5

repro:asexual reproduction

Answer 5

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

Question 6

what is gametangium

Answer 6

The structure in which gametes are formed

Question 7

what is synkaryon

Answer 7

Karyogamy - In this stage the nuclei present in the cell fuse with each other to form
a diploid nucleus which is known as synkaryon.

Question 8

types of sexual repro

Answer 8

-gametangial contact
-gametangial copulation
-somatogamy
-spermatization

Question 9

describe gametangial contact

Answer 9

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.

Question 10

describe gametangial contact

Answer 10

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.

Question 11

describe spermatization

Answer 11

Some fungi form uninucleate thin walled non motile spore like bodies. These spores are
called spermatia or Pycniospores (nonmotile male gametes).

Question 12

describe somatogamy

Answer 12

In it sex organs are not formed only two hyphae come close to each other and their cells
get fused.

Question 13

classes of phycomycetes

Answer 13

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.

Question 14

explain repro in ascomycetes

Answer 14

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

Question 15

types of ascocarp

Answer 15

-cleistothecium
ball shape

-perithecium
flask shape

-apothecium
disk shape

Question 16

explain ascospores

Answer 16

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.

Question 17

examples of ascomycetes

Answer 17

(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.

Question 18

features and uses of yeast

Answer 18

in sugar solution it undergoes rapid multiplication and forms pseudomycelium

-used in bakeries and breweries
(saccharomyces cerevisiae)

Question 19

what is the dolipore septum in basidiomycetes

Answer 19

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.

Question 20

what is clamp connection b/w cells in basidiomycetes

Answer 20

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.

Question 21

sexual repro in basidiomycetes

Answer 21

spermatization
somatogamy

Question 22

explain basidospore s

Answer 22

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

Question 23

in which fungi spermatisatin takes place

Answer 23

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)

Question 24

examples of basidiomycetes

Answer 24

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.

Question 25

name the causative agents of
(i) red rot of sugarcane
(ii) early blight of potato

Answer 25

(i) colletotrichum falcatum
(ii) alternaria solani

Question 26

what causes ringworm foot disese in humand

Answer 26

Trichophyton, Microsporum and Epidermophyton cause “Ringworm”

Question 27

how do fungal hyphae penetrate into hosts

Answer 27

with the help of enzymes

Question 28

which of the following is a form class

Answer 28

-> deuteromycetes

Question 29

what is clycospirin A? what it is used for>

Answer 29

Cyclosprin A, that is used as an immunosuppressive agent in organ-transplant patients is
produced by the fungus Trichoderma polysporum.

Question 30

what are statins? what it is used for?

Answer 30

Statins produced by the yeast
Monascus purpureus have been commercialised as blood-cholestrol lowering agent.