1) Fungi are a diverse group of eukaryotic organisms that lack chlorophyll and include mushrooms, molds, and yeasts. They obtain nutrients by absorbing organic compounds from dead or living organisms.
2) Fungi reproduce both asexually through spores and sexually through the fusion of gametes. Common asexual reproduction methods include the formation of sporangiospores, chlamydospores, and oidia.
3) The fungus Mucor is classified under the kingdom Mycota, division Eumycotina, class Phycomycetes. It is a saprophytic fungus that reproduces asexually through sporangiospores formed on sporangioph
2. General characteristics of fungi
They are large and diverse group of eukaryotic
organism.
They are non-vascular, non green, multicellular (except
yeast) and heterotrophic organisms.
The vegetative body of fungi is thallus.
The thallus consist of long, brached filaments called
hyphae. The mass of hyphae is called mycellium.
The cell wall is made up of fungal cellulose or chitin.
3. General characteristics of fungi contd…
Reserve food is in the form of glycogen and oil.
They reproduce by vegetative and asexual methods.
Sex organs are usually unicellular and non jacketed.
Embryo is not formed after fertilization.
They are decomposers of the environment.
4. Resemblances between algae and fungi
Both found in aquatic and semi aquatic habitat.
Have thallus body.
Vascular tissue absent.
Reproduce by spore during favorable condition.
Sex organs are unicellular, simple, non- jacketed.
Embryo not formed.
5. Mode of nutrition in fungi
Fungi lack chlorophyll and they depend upon other
organism for their food. (heterotrophic mode of
nutrition)
Their nutrition involves absorption of soluble substances.
They are either saprophytes or parasites or symbionts.
6. Mode of nutrition in fungi contd..
1. Saprophytic fungi:
They absorb food from dead and
decaying organic matter.
Some of them die without
decaying organic matter are called
obligate saprophytes. Eg. Mucor.
Some other have saprophytic
mode of nutrition but also live
parasitically called facultative
parasites. Eg. Fusarium, Pythium
Mucor
Fusarium
7. Mode of nutrition in fungi contd..
2. Parasitic fungi:
They obtain their food from the
host or protoplasm of the living
plants or animals.
The parasites which only grow in
living cells are called obligate
parasites. Eg. Erysiphae, Puccinia,
etc.
Some other fungi after death of
host are able to take their food
from dead and decaying body are
called facultative saprophytes. Eg.
Some smuts.
Erysiphae
Smut
8. Mode of nutrition in fungi contd..
3. Symbiotic fungi:
Some fungi from partnerships with
other group of plants by which both
the plants and fungi are benefited.
This type of association is called
symbiosis and such fungi are called
symbiotic fungi. E.g. Mycorrhiza.
Here the fungi get shelter and food
from the plants and fungi helps the
plant to absorb water and minerals. Mycorrhiza
9. Reproduction in fungi:
By vegetative, asexual and sexual methods.
Vegetative Reproduction
a) Fragmentation: mechanical injury or decay leads to the breakdown of
mycelium into many fragments. Each fragment grow into a complete
mycelium.
b) Budding: Parent cell produces a small protuberance and grow into a
bud. Bud later detached and forms a new individual. It is common in
yeast.
c) Fission: Cells of unicellular fungi divide into two daughter cells
amitotically.
10. Asexual reproduction:
It takes place by the formation of spores.
a) zoospore:
Thin walled, uninucleated motile or flagellated spores
formed inside zoosporangium.
Each zoospore germinate into a new mycelium.
E.g. Pythium, Albugo
11. b) Aplanospores or sporangiospores:
Non-motile, thin walled spores produced
in sporangia in large number. Eg. Mucor
C) chlamydospores:
Thick walled, resistant spores formed by
accumulation of protoplasm, rounding
off and secretion of thick wall at place
along the hyphae.
Developed from terminal or intercalary
cells
Released after death of hyphae and
remain viable for several years. Eg.
Mucor, Fusarium, Agaricus, etc.
12. d) Oidia or arthrospores:
In highly nutritious medium, hyphae of
some fungi split up into numerous
small, oval or rounded fragments called
oidia. Eg. Rhizopus, Mucor
e) Conidia:
Non- motile thin walled spores
developed exogenously at the tip of
special hyphae called conidiophore.
May be formed singly or in chain
Eg. Aspergillus, Penicillium
13.
14. Sexual reproduction
Most of the fungi reproduce sexually except fungi imperfectii
(Deuteromycetes).
It occurs by fusion of 2 gametes and their nuclei of opposite mating
types.
It involves:
a. Plasmogamy
b. Karyogamy
c. Meiosis.
The product of meiosis is called as meiospores which acts as
sexual spores and germinate to give mycelium.
15. Sex organs-
In fungi sex organ called as gametangia (unicellular and
naked)
Homothallism- sexual reproduction may occur in the sex
organs formed on different hyphae of same mycelium.
Heterothallism- sexual reproduction involves sex organ
formed on hyphae of 2 different mycelia.
16. Depending upon the nature of gametes, sexual reproduction
in fungi takes place by following methods.
1. Planogametic copulation: The planogametes are motile
gametes of fungi. The fusion of planogametes takes place
by following methods.
a. Isogamy
b. Anisogamy
c. Oogamy
17. 2. Gametangial contact:
Male sex organ (antheridia) and
female sex organ (oogonia) come in
contact.
Content of male gametes passes to
female gametes through fertilization
tube to form oospore.
3. Gametangial copulation:
Male and female gametangia fuse
directly resulting in the formation of
thick walled zygospore.
18. 4. somatogamy:
It involves fusion of two vegetative or
somatic cells without forming sex
organs. Eg. Agaricus.
5. Spermatogamy:
Male gametes are small and non
motile called spermatia.
Female gametangium forms a
receptive outgrowth called trichogyne.
Spermatium is carried to trichogyne by
various agents and the content of
spermatium are transferred to
trichogyne.
21. 1) Oomycetes:
Mostly parasitic.
Mycelium is coenocytic.
Asexually reproduce by zoospore
Sexual reproduction- oogamous.
Gametes are non flagellated.
Sexual reproduction by gametangial
contact.
Oospore is formed after fertilization.
Egs: Phytophthora, Albugo, etc.
22. 2) Zygomycetes ( conjugation fungi)
Mostly saprophytes, rarely parasites.
Mycelium which is well branched and
coenocytic.
Absence of motile cells.
Asexual reproduction takes place by
sporangiospores, aplanospores,
conidia.
Sexual reproduction by gametangial
copulation resulting in formation of
zygospores.
Egs: Rhizopus, Mucor
23. 3) Ascomycetes (sac fungi)
Mostly terrestrial occurring as saprophytes
or parasites.
Have well developed, branched, septate
mycelium except yeast (unicellular).
Asexual reproduction by non- motile spores
(conidia, oidia, chlamydospores).
Sexual reproduction by gametangial
copulation or gametangial contact.
Produce sexual spores (ascospores) within
sac like ascus.
Absence of motile cells.
Egs. Saccharomyces, Penicillium, Aspergillus
24. 4) Basidiomycetes:
Saprophytes or parasites.
Mycelium branched and septate.
Two kinds of mycelium: primary
(monokaryotic) and secondary (Dikaryotic).
Presence of dolipore septum and clamp
connection.
Asexual reproduction by fragmentation,
budding, oidia, conidia, chlamydospores.
Produce basidiospores at club shaped
basidium during sexual reproduction.
Absence of motile cell throughout lifecycle
Egs: Mushrooms, Puccinia (rust), Ustilago
(smut)
25. 5) Duteromycetes (fungi
imperfectii)
Saprophytes as well as parasites.
Unicellular as well as multicellular.
Mycelium consists of well developed,
septate, branched hyphae.
Asexual reproduction by conidia.
Sexual stages are unknown or may
not exist. Therefore, they are called
Fungi imperfectii.
Egs: Alternaria, Fusarium, etc.
26. MUCOR
Systematic position
Kingdom : Mycota
Division : Eumycotina
Class : Phycomycetes
Sub-class : Zygomycetes
Order : Mucorales
Family : Mucoraceae
Genus : Mucor
C.N.- Pin mould or Black mould
27. Occurrence
Saprophytic fungus and
worldwide in distribution.
Commonly called Pin muold,
Dung mould or Black mould.
It occurs on bread, jams, cheese,
pickles, animal dung, rotten
fruits, decaying vegetables,
leather, humus soil and other
organic materials.
Some species grows as
facultative parasite.
28. Morphology (Vegetative structure)
Vegtative body of Mucor composed of mass of white
or cottony, delicate thread like structure Called
mycelium.
Individual thread of mycelium is hypha.
Hyphae are long, slender, branched and coenocytic
filaments.
The septa formation takes place in old hyphae at the
time of formation of reproductive structures.
29. Morphology (Vegetative structure) cont….
Mucor consists of 3 kinds of hyphae:
a) Prostrate: branched and spread in
all directions on the surface of
substratum
b) Subterranean: much branched and
smaller that penetrate substratum
spreading inside it. Helps in
absorption and fixation
c) Aerial: Erect hyphae arise singly
from prostrate hyphae. They bear
sporangia at their tip, so called as
sporangiophore and helps in asexual
reproduction.
30. Morphology (Vegetative structure) cont….
Hyphae of mycelium is coenocytic.
Hyphal wall- chitin or fungal
cellulose.
Cytoplasm is surrounded by
selectively permeable plasma
membrane.
Highly vacuolated.
Consists of golgi body, mitochondria,
ribosomes, ER, other membrane
bound organelles.
Reserve food material- glycogen and
oil.
31. Reproduction
Reproduces by vegetative, asexual and sexual methods.
1. Vegetative reproduction:
By Fragmentation:
2. Asexual reproduction:
a) By sporangiospores or spores:
32. a) By sporangiospores or
spores cont…
Minute, brownish black,
multinucleate spores
produced in sporangium.
At maturity, the prostrate
hyphae give erect, aerial
hyphae which are called
sporangiophores.
At the tip of each
sporangiophore,
protoplasm is collected
and swells up to form
sporangium.
33. a) By sporangiospores or
spores cont…
The peripheral protoplasm
of sporangium is denser and
central is vacuolated.
The central portion of
sporangium is dome shaped
and sterile called columella.
The peripheral protoplasm
undergoes cytoplasmic
cleavage to form
multinucleate segments of
protoplasm.
Each segment rounds off
and secrets a dark wall
around it to form
sporangiospore.
34. a) By sporangiospores or
spores cont…
At maturity, columella swells
due to more absorption of
water from substratum, that
gives pressure to the wall of
sporangium.
The sporangial wall ruptures
and sporangiospores are
released out.
On getting suitable condition,
the spores germinate to give
rise a new haploid coenocytic
mycelium of Mucor.
35. b) By Chlamydospores
During unfavourable condition,
protoplasm collects at certain place
in the hyphae and such areas get
swollen.
The swollen areas round off and
develop a thick wall around them,
called chlamydospore.
During favourable condition,
chlamydospore germinate and form
new filament.
36. c) By Oidia
In liquid medium rich in sugar and
acidic pH, the hyphae become
septate.
The cells round off and separate to
form oidia.
When taken into solid medium,
oidia produce new mycelium.
Oidia again can multiply by budding.
This stage is called torulla stage.
37. Sexual Reproduction
Mucor is heterothallic and consists of mycelia with two
mating types (+) and (-).
Sexual reproduction takes place by gametangial copulation
under unfavorable condition.
38. Sexual Reproduction
Process:
Presence of compatible hyphae on the
same medium stimulates the formation of
trisporic acid.
Trisporic acid induces the formation of
long aerial or sub aerial hyphae called
zygophores. Zygophore of compatible
strains bend towards each other and come
in contact at several points.
Small protuberances arise at the place of
contact and grow into long, club shaped
progametangia.
39. Sexual Reproduction
A septum appears in each progametangium
which cuts it into terminal gametangium and
basal suspensor. The multinucleate protoplast
of gametangium behave as coenogamete.
The contact wall between two gametangia
dissolve and both gametangia form a single
fusion cell.
The two gametes fuse to form a zygote having
a number of diploid nuclei; the unpaired
nuclei disintegrate.
The zygote grow in size, becomes rounded
and secrets a wall inner to the wall of fusion
cell. The structure is called zygospore.
40. Sexual Reproduction
Zygospore is dark brown or black in colour having outer thick
wall (exosporium) and inner thin wall (endosporium).
Zygospore has dense cytoplasm containing a number of
diploid nuclei, cell organelles and food reserves.
Germination of zygospore.
Soon after the formation of zygospore meiosis takes place
and all the haploid nuclei except one degenerate.
The remaining nucleus divides many times results to the
formation of many nuclei of same strain.
The protoplast of zygospore swells up. Outer wall rupture
and comes out in the form of vertical germtube called
promycelium.
41. Sexual Reproduction
Germination of zygospore cont…
The tip of the promycelium swells up
and forms a rounded germ-
sporangium, which produces non
motile uninucleate haploid
germspores.
The germspores are liberated and
germinate on suitable substratum to
form new mycelium.
42. Economic importance of Mucor
Positive effects:
Mucor spp. living in soil take part in decaying organic matter
and maintain soil fertility.
Alcoholic fermentation of rice and other food.
Citric acid can be prepared from molases with the help of
Mucor.
Negative effects:
Rotting of fruits and vegetables.
Mucor pusillus cause myosis (fungal disease) of internal organs
seriously.
Spoilage food stuffs.
43. YEAST
Systematic position
Kingdom : Mycota
Division : Eumycotina
Class : Ascomycetes
Order : Endomycetales
Family : saccharomycetaceae
Genus : Saccharomyces
44. YEAST
Occurrence:
Includes about 30 species and cosmopolitan in distribution.
Saprophytic fungi found in organic matters.
Common on rotting fruits, cane juices, nectaries of flowers,
sweets, decaying organic matters, etc. Also found in animal
excreta and humus of soil.
Some species are parasitic to plants and animals.
3 types-
budding yeast (Saccharomyces)
fission yeast (Schizosaccharomyces)
halobial yeast ( both budding and fission) Saccharomycoides
45. Morphology/ Structure
Non-mycelial, unicellular fungi.
In some cases, rapid budding
results up to 100 cells remaining
in chain and look like mycelium
called pseudomycelium, which is
temporary.
Shape: Spherical, oval or
cylindrical.
Size: 3-15 µm (length); 2-10 µm
(breadth).
White or cream colored.
46. Morphology/ Structure cont..
Cell wall: thin, rigid outer protective covering made up of
chitin.
Inner to cell wall- cell membrane which encloses
protoplasm.
Protoplasm consists of nucleus and other cell organelles
like mitochondria, ER, Dictyosome, ribosomes, etc.
Reserve food material is in the form of glygogen or fats.
A large central vacuole is found in Saccharomyces
cerevisiae.
Nucleus lies at one end of vacuole. From nucleus, dark
staining fine threads of unknown significance are spread
over the surface of vacuole. Such type of vacuole is called
nuclear vacuole.
49. Asexual reproduction
By Endospore formation
Occurs during unfavorable condition
(scarcity of food and drought).
The protoplast of the vegetative cell divides
into four parts.
Each part become rounded by thick wall
and acts as endospore.
They remain dormant in unfavorable
condition and produce chain of cells in
suitable condition.
50. Sexual Reproduction
Distinct sex organs are absent.
Occurs by conjugation between two cells or ascospores at
the end of growing season under unfavorable condition.
After fusion of two haploid cells, diploid cell is formed.
The diploid cell sooner or later functions as ascus in
which meiosis occur and haploid ascospores are
produced.
51. On the basis of mode of sexual reproduction
Three types of life cycle
1. Haplobiontic life cycle
2. Diplobiontic life cycle
3. Haplodiplobiontic life cycle.
52. Haplobiontic life cycle
Occurs in Schizosaccharomyces octosporus (fission yeast).
Haploid phase is dominant.
Diploid phase is short and represented by zygote only.
54. Diplobiontic life cycle
Occurs in Saccharomycoides ludwigii (budding yeast).
Diploid phase is long and dominant and represented by
somatic cells.
Haploid somatic cells cannot be observed.
Short haploid phase is represented by ascospores.
56. Haplodiplobiontic life cycle
Occurs in Saccharomyces cerevisiae (Baker’s yeast).
Both haploid and diploid phase are equally dominant.
Vegetative cell is both haploid and diploid.
58. Economic Importance of Yeast
1. Positive effects:
Yeasts produce enzymes zymase and
invertase and helps in fermentation. So
they are used in alcohol industries
Saccharomyes cerevisae is used in backing
industry as it can make bread soft and
porous.
Yeast can synthesize protein, fat and
vitamin B complex.
Some yeasts are used to cure skin
diseases.
Along with bacteria, yeast gives
characteristics flavors in coca beans ( a
type of plants)
59. Economic Importance of Yeast
2. Negative effects:
Yeast spoils food, vegetables and fruits.
Cause many plant and animal disease.
Some yeast attack silkworm and kill them.
60. Economic importance of fungi
Fungi have both positive and negative role in different areas.
1. In agriculture:
Fungi and soil fertility: saprophytic fungi decompose
organic matter and enhance fertility of soil.
Fungi as Mycorrhiza: Some fungi form symbiotic
association with roots of higher plants and help them in
absorption of nutrients.
Control soil borne pathogens and insects: Some fungi
obtain their nutrients by killing protozoans, nematods and
other pests which help to control disease caused by them.
61. Economic importance of fungi
1. In agriculture:
Plant and animal disease: Several fungi cause crop
disease resulting in great economic loss.
Puccinia graminis cause black stem rust in wheat
Albugo candida cause white rust of crucifer
Phytopthera infestens cause late blight of potato
62. Economic importance of fungi
2. In medicine and human health
Antibiotics:
Penicillin from penicillium
Alkaloids:
Ergotin from Claviceps purpurea.
Human disease:
Aspergillus fumigats: Aspergillosis
Trichophyton sp. And Microsporum sp :
Ring worm
63. Economic importance of fungi
3. In industry:
Saccharomyces cerevisae helps in alcoholic
fermentation and used in alcohol industries. It is also
used in baking industries to make bread porous.
Penicillium roqueforti used for production of cheese.
Many organic acids are produced commercially
Lactic acid by Rhizopus oryzae
Citric acid by Aspergillus niger
Many enzymes can produced commercially
Invertase by Saccharomyces cerevisae
Amylase by Aspergillus niger
64. Economic importance of fungi
3. In industry:
Gibberellins (hormone) produced from
Gibberrella fujikuroi.
Many pigments and vitamins are also
produced.
4. Fungi as food:
Many mushrooms like Agaricus campestris, A.
bisporous, Morchella, etc. are edible.
5. Fungi in academic works : Neurospora
6. Cordyceps sinensis (Yarsa gumba) is a high value
medicinal fungus and commonly called
caterpillar fungi.