Including Mental Health Support in Project Delivery, 14 May.pdf
The plant kingdom (alage+bryophyta+pteridophyta)
1.
2.
3. Algae
• Range in size from microscopic to single celled organisms to large seaweed.
• Simple thalloid (without differentiation)
• Most are aquatic and autotrophic and lack many of the distinct cell and tissue
types, such as stomata, xylem, and phloem, which are found in land plants.
16. Unicellular / colonial / filamentous
Pigments - chlorophyll a and b
chloroplasts may be discoid, plate-like, reticulate,
cup-shaped, spiral or ribbon-shaped
Store bodies – pyrenoids, oil droplets
Rigid cell wall made of an inner layer of cellulose
and an outer layer of pectose
17. Vegetative reproduction
by fragmentation
Asexual reproduction by
zoospores
Sexual reproduction by
isogamous /
anisogamous /
oogamous
e.g. Chlamydomonas,
Volvox, Ulothrix,
Spirogyra and Chara
Volvox
18.
19. Marine habitats
Vary in shape and size from simple branched,
filamentous forms (Ectocarpus) to profusely
branched forms kelps about 100 m height.
Body consists of holdfast, a stalk, stipe and frond.
Pigments - chlorophyll a, c, carotenoids,
xanthophylls, fucoxanthin
Food is stored as carbohydrates in the form of
laminarin or mannitol.
Cell wall covered by algin, a gelatinous coating.
20. Vegetative reproduction
by fragmentation.
Asexual reproduction by
biflagellate zoospores.
Sexual reproduction may
be isogamous,
anisogamous or
oogamous
e.g. Ectocarpus,
Dictyota, Laminaria,
Sargassum and Fucus
Sargassum
21.
22. Habitat – some fresh water, brackish
water, mostly in salt water
Pigments - chlorophyll a and d,
r-phycoerythrin
Food is stored as Floridean starch,
which is similar to amylopectin and
glycogen in structure.
Vegetative reproduction is by
fragmentation
Asexually by non-motile spores
Sexually by non-motile gametes
e.g. Polysiphonia, Porphyra,
Gracilaria, Gelidium
Gracilaria
Gelidium
29. General characteristics of bryophytes
• Bryo- gr. moss. & ~16,000 species.
• Non-vascular plants
• Advancements over algae: cuticle, multicellular
gametangia, stomata
• Habitat: they require moist environment for active growth
and sexual reproduction
• The diverse bryophytes are not a monophyletic group.
Several lines of evidence indicate that these three divisions
diverged independently early in plant evolution, before the
origin of vascular plants.
• Mosses are the bryophytes most closely related to vascular
plants.
• The gametophyte is the dominant generation in the life
cycles of bryophytes
• Note, the name Bryophyta refers only to one division, but
the informal term bryophyte refers to all nonvascular
plants.
Bryophytes are represented
by three phyla:
Hepatophyta – liverworts;
Anthocerophyta – hornworts;
Bryophyta - mosses
30. They lack true roots.
They anchor themselves in
the soil by root-like
structures called rhizoids.
Rhizoids are relatively simple,
sometimes multicellular filaments of
thin-walled cells that extend from the
photosynthetic tissue into the soil
Lack vascular tissues
No lignified tissues/
Amphibians of plant kingdom. Need Water
for their fertilization
31. Mode of nutrition : autotrohic as well as
saprophytic.
Plant body is thallus (not differentiated into
Root,stem and leaf) e.g Marchantia,Anthoceros.
Sporophyte has three parts : foot,seta,capsule.
The gametophyte bears multi-cellular and
jacketed sex organs (antheridia and
archegonia).
Sexual reproduction is oogamous type.
Multi-cellular embryo develops inside
archegonium.
Sporophyte differentiated into foot, seta and
capsule.
Capsule produces haploid meiospores of similar
types (homosporous).
Spore germinates into juvenile gametophyte
called protonema.
Progressive sterilization of sporogenous tissue
noticed from lower to higher bryophytes.
32. •The bryophytes show alternation of generations - the haploid gametophyte (producing
gametes for sexual reproduction) alternates with diploid sporophyte (producing spores for
asexual reproduction).
•Gametophytes homothallic or heterothallic.
33. First time demonstrated by
Hofmeister(1851)
Life cycle of a plant is called alternation of
generations.
Haploid and diploid generation
alternating during life cycle
-Sporophyte ie. Multicellular ,
spore forming diploid plant str.
-Gametophyte ie. Multicellular
haploid plant structure, forms
gametes.
What is alternation of generations?
Bryophytes(mosses and ferns)
- dominant generation-haploid phase
- main plant body is composed of
gametophyte
34. Better chance for survival
Better adapted to environment
Newer varieties develop
Variations are produced during
meiosis
Significance:
35. Alternation of generation in
Bryophytes
Haploid phase (n) is gametophytic generation
or sexual phase.
Bears reproductive organs
- produce antherozoids and eggs
Gametophytic stage - longer lived
,conspicuous as compared to sporophyte.
Gametophytic stage is dominant in life cycle.
Diploid phase (2n) or the sporophytic stage
- gametic union results into the formation of
zygote which develops into sporophyte.
Meiosis in SMC(spore mother cell)
- spore formed
- germinate to form gametophyte again.
- cycle continues with alternation b/w
gametophye and sporophyte.
Sporophyte dependent on gametophyte
Heteromorphic alternation of generation.
39. • The male plant produces clusters of elongate antheridia
which contain thousands of flagellated sperm.
Gametangia and gametes can be embedded in the gametophyte tissue as shown here, or
attached at the surface of the gametophyte.
Antheridium (Sperm-bearing
Organ) with an outer row of
sterile (nonsperm-forming)
cells enclosing inner fertile
cells, each of which becomes
a sperm gamete.
Gametangia –organs that produce gametes.
40.
41. Moss spore capsule (Tortula muralis var. muralis)
SEM
Coloured
scanning electron
micrograph
(SEM) of part of
the opening
mouth of a
capsule (spore
case) of moss.
Mosses reproduce
by means of
spores at certain
times during their
life cycle. The
spores are
dispersed from
the mouth of the
capsule, dispersal
aided by the
wind.
Magnification
x1380
42. Marchantiophyta (Hepaticophyta)- liverworts
• Hepato- gr. liver. & 6,000 species.
• Gametophytes thalloid or leafy, often bilaterally symmetrical and lobed
• Simplest of all living plants.
• Rhizoids single celled.
• Reproduction:
- Asexual- with pieces of tissue call gemma, which are bounced by rain out of
gemma cups.
- Sexual- haploid gametophyte, diploid sporophyte
• Sporophytes without stomata, but have pores.
• Specialized conducting tissue absent.
• Sporangium with dehiscent capsule, elaters present in some to disperse spores.
• Most cells contain numerous chloroplasts.
• Habitat- moist, some aquatic, temperate and tropical. Examples- Marchantia and Riccia.
43. • asexually with pieces of tissue
call gemma, which are bounced
by rain out of gemma cups.
gemma cups
47. Anthocerotophyta- hornworts
• Antho- gr. flower, keras- gr. horn. & 100 species
• Hornworts are similar to liverworts except each
cell only has one large chloroplast rather than
many smaller ones, and the sporophytes are
elongated capsules.
• Rhizoids single celled.
• Gametophytes thalloid.
• Specialized conducting tissue absent.
• Sporophytes with stomata.
• Sporangia dehisce to disperse spores, elater-like
structures present.
• Habitat- moist temperate and tropical.
• Example- Anthoceros Magnification approximately 200x
48. The long, slender
sporophyte generations
grow upward from the
thallus and are typically
0.5 to 12 centimeters in
height.
Hornworts often have long,
pointed sporophytes
(resembling horns) that
rise from the thalloid
gametophytes.
49. Bryophyta- mosses
• Sporophytes with stomata.
• Specialized conducting tissue- leptoids
and nonlignified hydroids.
• Gametophytes leafy.
• Rhizoids multicellular.
• Sporangia with dehiscent capsules.
• Most cells with numerous chloroplasts.
• Habitat- moist and dry, temperate and
tropical, some aquatic.
• 9,500 species.
• Example- Polytrichum, Sphagnum,
Mnium.
50. The bryophytes reproduce by
vegetative, sexual and asexual modes
of reproduction. The gametophyte
reproduces sexually by formation of
gametes whereas the sporophyte
reproduces by the formation of spores,
therefore the mode of reproduction is
asexual.
Reproduction
Types Of Reproduction
1=Vegetative reproduction
2=Asexual reproduction
3=Sexual reproduction
51. In some species asexual reproduction takes
place by the vegetative methods of
fragmentation and genome. However
asexual spores like endospores or akinetes
produced in algae are absent.
A mature sporogonium consists of a basal
swollen foot, a stalk or seta, and a spore-
producing structure, the capsule. The
capsule comprises of sporogenous cells
surrounded by a layers of sterile cells.
These cells undergo divisions repeatedly
and last generation of cells is called spore
mother cells which undergo meiosis to
produce tetrads of haploid spores. The
spores are non motile, cutinized, wind
disseminated and alike, therefore the
bryophytes are homosporous. In most
cases, e. g., Riccia and Marchantia, sterile
cells called elators are also produced
along with spores.
Asexual Reproduction
Vegetative Reproduction
52. The sexual reproduction is oogamous type.
The gametes are produced in multicellular
sex organs. The male gametes are small and
motile, while the female gametes are large
and non motile.
The sex organs are antheridia and
archegonia. These are multicellular and each
sex organ is protected by an outer wall of
sterile cells surrounding sex cells. Both kinds
of sex organs may develop on the same plant
(monoeious or homothallus) or on different
plants (dioecious or heterothallic).
Each anthridium is usually club
shaped. It contains androcytes or antherozoid
mother cells surrounded by a single layer of
sterile jacket cells. Each androcyte
metamorphoses into a motile biflagellate
antherozoid or male sperms. The archegonia
are usually flask-shaped. Each archigonium
consists of a basal swollen portion, the venter
and an elongated part, the neck. An axial row
of cells surrounded by jacket of sterile cells is
present in the neck and venter. It consists of
few neck canal cells, a ventral canal cell and
an egg or oosphere.
Sexual Reproduction:
53. Fertilization: Water is essential
for fertilization. The jacket if
mature antheridium ruptures
liberating the sperms. The
motile flagellated sperms swim
in the film of water and reach
the neck of an archi gonium. In
the meantime axial row of the
neck canal cells disorganize and
the tip of the archigonium
ruptures opens. The
antherozoids enter the neck and
swim down to the egg. One of
these sperms fertilizes the egg
to produce zygote
56. Bryophytes as Fuel
and in Horticulture
• Liverworts and mosses have
long been tried and used as a
fuel in developed countries
like Finland, Sweden, Ireland,
West Ger-many, Poland and
Soviet Union.
• Peat a brown, soil-like material
characteristic of boggy, acid
ground, consisting of partly
decomposed vegetable matter.
• Peat is suitable for production
of low and intermediate BTU
gas as well as hydrogen,
ethylene, natural gas,
methanol and Fisher Tropsch
gasoline.
• Peat mosses are best suited
for the production of
methane, and peat is likely to
become an important source
of fuel for production of
heat,methane, or electricity in
the future.
• There is a long
tradition of use
of bryophytes in
horticulture as
soil additives,
because of
their high water
holding
capacity and to
air. Peat is an
important soil
conditioner and
is commonly
used for
agricultural and
horticultural
purposes
around the
world.
57. Bryophytes as ornamental plant
• Bryophytes have also been used for green
house crops, potted ornamental plants and
seedlings, and in garden soil.
58. Skin
treatment
Sphagnol’chilblains,
scabies, acne and other
forms of skin diseases
Help to cure
ringworms.
Ash of moss is mixed with
honey and fat to treat cuts,
burns and wounds
Use for curing for
allaying arising
from insect bites.
Medicinal Uses
59. Role of Bryophytes in
Different Ways
PEAT
FORMATION
SEED BEDS
FOOD AND
SHELTER
POLLUTION SOIL
CONSERVATION
INDICATOR OF
soil PH
INDICATOR OF
ACID RAIN