BRYOLOGY
·
Famous Indian Bryologist: DK Singh
· Hepaticae: Each cell in the thallus contains many chloroplasts; the
chloroplasts are without pyrenoids.
·
Anthocerotae: Each cell of the thallus possesses a single large chloroplast
with a pyrenoid.
·
In Moss, primary protonema is haploid and gametophytic
·
diploid in moss
plant- Spore mother cell
·
Elators and pseudoelators in the capsules of bryophyte are meant for Spore dispersal
·
sporangia of mosses? Sporocytes undergo meiosis to produce
spores
·
When moss
spore germinate they form Protonema , then a leafy gametophyte
·
The
sporophyte contains pseudoelators in Anthoceros
·
Funaria: The conducting tissues do not consists Xylem and Phloem tissues in
·
class “Metzgeriidae” belongs Jungermanniopsida
·
Riccia:
bryophyte, the sporophyte at maturity has reduced to the sporangia.
· Liverworts
and mosses grow on soil, on dampy soil, on rocks, and on tree trunks and also
in water
· Pteridophytes and bryophytes common characters :multicellular sex organs with sterile jacket cells
Porella- xerophytic bryophyte
Marchantia, the liverwort is characterized by
·
Female organs are known as archegonia
and are protected by the thin surrounding perichaetum
·
Antheridia are enclosed by a protective
layer of cells called the perigonium
·
Male gametes are produced in numerous
and multiflagellate
·
The sporophyte
hangs down from the underside of the archegonium.
Anthoceros
·
Bryophyte with Nostoc clony can be seen in the thallus : Anthoceros
·
Pseudo-elaters are present in Anthoceros
Funaria:
·
can produce an embryo during sexual
reproduction
·
The spore dispersal mechanism of Funaria-
Peristomial teeth
Sphagnum
·
most primitive
water conducting structures known as hydroids are found in Sphagnum
· Bryophyte is known for its capacity to hold water and as a source of peat: Sphagnum
PTERIDOLOGY
·
In the
prothallus of the fern plant , The nuclei of all cells including sex organs
and gametes have monoploid number
·
The
protostele of Lycopodium
species shows variations with respect to its shape and arrangement of vascular
tissue such as actinostele, plectostele, mixed protostels and plectosteles.
· Dehiscence of sporangia takes place by a vertical splitting in Selaginella
Classification of Pteridophyte
· Pteridophytes with endosporic gametophytes
will be heterosporic
· In megaphyllous pteridophytes emergence of leaf traces leaves gaps in the stele.
·
Stelar types
in Pteridophytes has leaf traces:
Dictyostele
·
Telome theory of Zimmermann
·
Telome concept has been used in understanding the origin and
evolution of the major groups of pteridophytes.
·
Overtopping -> Reduction -> Plantation -> Syngenesis
or webbing ->Curvation.
·
series led to the evolution of
megaphyllous leaves:
·
Over topping - planation – syngenesis
·
Gametes are prouced in Prothallus
·
Vascular bundle in which xylem
surrounds phloem is termed as Amphivasal.
·
Antherozoids are spirally coiled and
multi- flagellated- Psilotopsida
·
Spores may be homosporous or
heterosporous - Lycopsida
·
Gametophytes are exosporic and green
- Sphenopsida
· Tree fern-Cyathea
Rhynia:
Rhynia has apical sporangium ,
Rhynia is a single-species genus of Devonian vascular plants , Rhynia
gwynne-vaughanii was the sporophyte generation of a vascular plant.
·
Haplostele,
actinostele, plectostele, medullated protostele alone are protosteles
Isoetes
·
A pteridophyte with the structures,
velum and foramen.
·
Prismatic tissue - Isoetes
Selaginella
·
Heterospous pteridophyte
·
Male gametes in Selaginella are biflagellate.
Rhynia
·
Fossil pteridophyte Rhynia major
belong to Psilophytales.
·
Rhynia belongs to devonian
·
is a pteridophyte without the
differentiation into true leaves and roots
Salvinia
·
is a rootless Pteridophyte.
·
The archegonia are deeply sunk in the
apical cushion. They have a very short neck, an egg cell, a venter canal cell
and a two nucleate neck canal cell.
Equisetum
·
Pteridophyte with elators
·
Peltate disc is the characteristic feature of strobilus
from the pteridophyta member
·
siphonostele having a single phloem
ring external to the xylem is called as ectophloic siphonostele.
·
Vallecular canals
and Carinal canals are the characteristic features of Equisetum
Marsilea
·
In the mature sporocarp of Marsilea, inner
parenchymatous zone cells gelatinise and form a gelatinous ring which helps
in the dehiscence of the sporocarp at maturity.
Osmunda
·
The maturity of sporangia within a
sorus is varied. where, the sorus type
·
is a simple i.e., all the sporangia develop
simultaneously
·
Tassel - Osmunda
Azolla
·
It is an aquatic fern
·
It hosts symbiotic nitrogen fixing
blue-green alga
Its vascular cylinder is siphonostelic
· Sporocarp - Azolla
GYMNOSPERMS
ü
Heterosporous
- microspores and megaspores, are typically produced in male ones or ovulate
cones, respectively.
ü
Cycads and
Ginkgo have motile sperm that swim directly to the egg inside the ovule,
whereas conifers and gnetophytes have sperm with no flagella that are conveyed
to the egg along a pollen tube.
ü
The mature
seed comprises the embryo, the endosperm which is haploid, serves as food
supplier with a seed coat.
·
Heterosporous
·
Generally xylem vessels are absent
·
In gymnosperms the endosperm is haploid
·
Softwood are wood of gymnosperm.
·
Largest ovules are found in
Gymnosperms
·
Manoxylic wood with large amount of parenchyma
·
The general pollination mechanism in
gymnosperms is: Anemophily
·
Pollination in gymnosperms occurs by wind.
·
A protective
covering in gymnosperms, which morphologically is equivalent to ovuliferous
scale, develops next to the integument: Epimatium
Pinus:
·
Gymnosperm with winged pollen
·
Winged seeds
are present
·
The seed known by the name ‘Chilgoza’, that is used as a dry fruit Pinus gerardiana
Welwitschia mirabilis: monotypic gymnosperm genus
·
a plant with a thick, short stem less
than 45 cm above the soil and a pair of large leathery leaves about two meters
long in the south coast of the walvis Bay in South Africa.
Gnetum- which is a woody climber - Gnetum ula
Ginkgo
·
Ginkgo biloba the only living fossil representative of
Gymnosperm
Cedrus
·
Deodar
wood, the strongest coniferous wood is obtained from Cedrus
Extra:
· Gymnosperms is a profusely branching shrub: Ephedra distachya
Economic Importance of Gymnosperms
·
An anticancer drug obtained
from Gymnosperm is Taxol
·
Ramenta -
Pteris
·
Terminal
Sporangium- Rhynia
·
Pycnoxylic
wood -Pinus
·
Ovules at
the tip of a stalk - Ginkgo