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MORPHOLOGY OF FLOWERING PLANTS
INTRODUCTION
You know that flowering plants are
multicellular organisms.
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They grow by cell division and their
morphological features and traits are genetically determined.
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Indeed though the angiosperms show
such a large diversity in external structure they're all characteristics of the
presence of roots, stems, leaves, flowers, and fruits.
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Morphology deals with the study of
forms and features of different plants organs like roots, stem, leaves, flower, seeds
fruits etc.
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Morphology play a crucial part in
the bracket of angiosperm. In this unit you'll learn about the important
morphological features of the flowering plants .
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We shall learn how to describe a
flowering plants, using exemplifications are modified to
serve specific requirements including defence from their adversaries.
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You'll get some idea of the
profitable significance of named plants
families.
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THE ROOT
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Roots are spherical, underground and
non-green part of the plants .
It's generally the descending portion of the plants axis I.e.,
it grows down into the soil.
·
It lacks bumps, leaves kids but
gives rise to endogenous side branches. Roots move in the direction of
graveness (geotropism) and against the direction of light (phototropism).
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Hence, the roots are said to be
appreciatively geotropic and negative phototrophic plants have
well- developed root systems.
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The main roots and its side form the
root system. There are three types of root system.
Valve ROOT SYSTEM
The primary root is directly
stretched from the radicle and grow inside the soil. (E.g. Dicots).
It side roots of several
orders that are appertained to as secondary, tertiary rootsetc.
The primary and its branches
constitute the valve root system.
Stringy ROOT SYSTEM
In monocotyledonous plants ,
the primary root is short-lived and is generally replaced by number of
discovery stringy roots.
These roots appear from base
of the stem and constitute the stringy binges system announcement seen in wheat
plants
.
Accidental ROOT SYSTEM
Some plants have specialized
roots called accidental roots. These roots develop from any corridor of the plants other
than the radicle e.g. Lawn, Monsters Banyan tree.
MAIN FUNCTION OF ROOTS
Immersion of water and
minerals from the soil.
Give Anchorage to the plants corridor.
Storehouse of reserve food material.
Conflation of plants growth
controllers.
REGIONS OF THE ROOT
ROOT CAP-The apex of the root is covered by a thimble-such like,
structure called root cap, it's multicellular and is made up of parenchymatous
cells.
REGION OF MERISTEMATIC ACTIVITY-This subcaste is many millimeter
above the root cap, the cell of this subcaste are thin walled, small, with
sense protoplasm.
REGION OF Extension-The cell proximal to the meristematic region
suffer rapid-fire extension and blowup and are responsible for the growth of
roots in length.
REGION OF Development-The cells extension zone gradationally separate and
develop. Hence, this zone proximal to region of extension is called the region
of development.
Morphology of Flowering Plants Class 11 notes NEET
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MODIFICATIONOF ROOTS
The roots are substantially involved
in immersion of water and minerals from the soil.
Roots in some plants sufferMODIFICATIONin
their shape and structure in order to perform function like respiration,
storehouse and protection.
STOREHOUSE ROOTS - In some plants the
primary valve roots is modified to store food and assumes colorful shapes e.g.
valve root of carrot, turnip, radish, beet and accidental roots of sweet potato
get blown and store foods.
RESPIRATORY ROOTS- In
some plants similar as Rhizopus growing in swampy areas,
numerous roots come out of the ground vertically overhead to get oxygen for
respiration. Similar roots are called pneumatophores.
MOUNT ROOTS- They
Aries from the branches of stem for furnishing mechanical support to heavy
branches, as pillarse.g. banyan trees.
STILT ROOTS- They
Aries from lower bumps of stem to support main axis and enter the soil
diagonallye.g. sugarcane, sludge.
STEM
The plants axis bears kids and shoots with leaves
and, at its rudimentary end, roots.
The stem conducts water,
minerals, and food to other corridor of the plants ,it may also store food, and
green stems themselves produce food.
The region bearing leaves present at
regular intervals on the stem and it’s branches are called bumps.
the part of the stem present
between the two bumps are called internodes.
A cub is defined as the
youthful immature, underdeveloped, compact shoot.
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Outstation Cub- The
cub present at the tip of the stem is called a terminal cub.
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AXILLARY Cub- The Leaf makes an angle with the
upper part of the stem, the angle made between the leaves and upper part of the
stem is called the axil.
FUNCTION OF THE STEM
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Stem bears and supports leaves,
flower and fruits.
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It conduct water and minerals
mariners from roots to leaves and fruits.
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The food manufactured in the leaves
transported to the roots, fruits and organs of storehouse through the
stem.
MODIFICATION OF STEM
· The stems of some plants in modified to perform different function in order to help to acclimatize to the present environmental condition.
Underground stem- Stem
is generally the upstanding part of the plants I.e. it's present above the ground but in some
PLANTS
it's modified for storing food material.
Rhizome- it grow
resemblant or vertical to soil face, gusto and turmeric.
Tuber- it's terminal portion of
underground stem branch which is swollen on account of food accumulation of
food, Potato.
Corm- It grows
vertically beneath soil face, colocasia, gladiolus and crocus.
Bulb- Stem is reduced
and slice shaped, onion lily garlic.
Stem tendrils- In
some PLANTS the axiliary cub present on the stem modify to
form tendrils. These are long, thin, thread like spirally curled sensitive
structure.E.g. pumpkins watermelon cucumber.
Nuisance- The
axillary kids of PLANTS like citrus and Bougainville lose their
capability to grow and form hard woody announcement refocused structure called
frustrations.
SUBAERIAL WEAK STEM
Neutralize- Submarine
plants similar as pistia and Eichhormia
contain a side branch which bear short internodes.
Sucker- In plants like
banana, pineapple the side branches appear from the rudimentary and underground
portion of the main stem.
Runners- It's stretched,
prostate branch with internodes and roots at bumps e.g. meadows.
Stolons- In plants
like mint and Jasmine a slender branch arises from the base of the main
axis.
Upstanding stem- Plants present
in thirsty modify their stem into smoothed or fleshy, spherical structure
called phylloclade. These structure carry out function of photosynthesis.
Morphology of Flowering Plants Class 11 PDF download
THE LEAF
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A Leaf is a side, generally
flattened structure borne on the stem.
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It develops at the knot and bears a
cub in its axil.
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It originates from the shoot apical
meristem and arranged in an acropetal order of the stem.
Corridor OF LEAF
A typical Leaf correspond of
Three corridor-
Leaf base –
The smallest rudimentary part of the Leaf by which the Leaf is attached to the
knot of the stems called Leaf base. The lead base may bear two side small Leaf
like structure called stipules. The base swells and is called
pulvinus.
Petiole-The
spherical stalk that joints the Leaf base with the Leaf blade ( lamella) is
called Petiole.
Lamella and Leaf blade- It green expanded part of the Leaf, Blade
is supported by the modes and veinlets. the prominent tone present in the middle
of the Leaf blade is called midrib.
VENATION
The lamella of Leaf blade contains
modes and veinlets. The arrangement of modes and veinlets in the lamella or Leaf
blade is nominated as venation.
Reticulate venation- The veinlets form a network. It
generally occurs in dicots similar as peepal, hibiscus.
Resemblant venation- The venation where the modes run resemblant to each other
within a lamian. It generally occurs in monocotes.E.g. banana.
anatomy of flowering plants ncert pdf
TYPES
OF LEAVES
Different types of leaves which live
in nature are
Simple
Leaf-The Leaf in which the Leaf blade
isn't divided or when incised.
Emulsion
Leaf-The Leaf in which the lamella or Leaf
blade is fully broken into distinct circulars is called emulsion Leaf.
Pinnately
emulsion Leaf- In pinnately emulsion Leaf, the
midrib forms a common axis called rachis.E.g. neem.
These are can be unipinnate,
bipinnate, Tripinnate and decompound.
Palmately emulsion Leaf-In palmately
emulsion Leaf, the circulars are attached to a common pointI.e. at the tip of
the petiole. Eg silk cotton.
These may be unifoliate, bifoliate,
trifoliate, quadrifoliate and multifoliate.
PHYLLOTAXY- The pattern in which the leaves arranged on the stem on its
branches is called phyllotaxy.
Phyllotaxy is of three types
these are following.
Indispensable
phyllotaxy- Single leaves present at each
bumps in an alternate fashion eg sunflower.
Contrary
phyllotaxy- A brace of leaves Aries at each
bumps on contrary side eg Guava.
Whorled
phyllotaxy- In this phyllotaxy further than two leaves aries at each
knot in an whorled circle eg nerium.
MODIFICATIONOF LEAVES
Leaves are generally
responsible for the devlopment of PLANTS body which process the miracle of
photosynthesis, transpiration gassy exchange etc.
At some times these condition are
unfavourable, leaves get modify and perform other function similar as
storehouse, protection, defence ,etc.
Leaf
tendrils- In some plants , leaves modify into long slendar, thread
like, sensitive structure called tendrils. Eg, peas, sweat peas.
Leaf
backbones- In some plants as aloe, cactus etc.
leaves modify into small, sharp-pointed structures called Leaf backbones.
Storage
Organ- In some plans similar as Onion
garlic, etc. Fleshy leaves store food and hence forms the storehouse organ in PLANTS .
Phyllodes- In certain PLANTS similar as Australian Acacia the leaves are
small and short lived.
These have green coloured leaves
like structure which perform the function of photosynthesis These are know as
phyllodes.
INFLORESCENCE
These are the group or cluster of
flowers arranged on a stem that's composed of the main branch or a complicated
arrangement of branches.
It's a modified part of the shoot of
seed plants where flowers are formed.
The variations can involve the
length and nature of the internodes and the phyllotaxis.
The variations in the proportions,
bumps, adnations, connations and reduction of main and secondary axes.
FUNCTIONS OF INFLORESCENCE
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These are complex structures with
numerous functions.
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They're present in flowers in such a
ways that allow for the transfer of pollen and optimization of the PLANTS ’s reproductive success.
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They give nutrition to the
development of fruits and flower.
TYPES
OF INFLORESCENCE
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Raceme The flowers are with pedicels
of about the same length, which are attached along the lengthen and unbranched
peduncle of the inflorescence (eg lily)
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Panicle The flowers are with
pedicels, which are attached along the branches arising from the peduncle of
the inflorescence (eg oats, rice, fescue)
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Corymb The flowers are with pedicels
of unstable length, which are attached along an unbranched, lengthen peduncle,
forming a flat- outgunned inflorescence (eg hawthorns).
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Umbel The flowers are with pedicles,
which are all attached at about the same point at the end of the peduncle this
is specifically called a simple umbel ( exemplifications onion,
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Head The flowers don't have
pedicels, and they all cluster tightly on the expanded tip of the peduncle
(eg-sunflower, daisy, marigold)
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Cyme The flowers with pedicels are
located at the ends of the peduncle and side branches as well as along the
length of the side branches
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Catkin The flowers have no pedicels,
are androgynous, and are at turned along the length of the peduncle (eg
hazelnut)
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Spadix The flowers have no pedicels
and are attached along the length of the thickened or fleshy peduncle.
THE
FLOWER
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The flower is the reproductive unit
in the angiosperm. It's a modified shoot meant for sexual reduplication.
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It consists of four curls which are
consecutively arranged on the thalamus or container.
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The four curls present in a flower
are calyx, corolla, androecium and gynoecium.
Harmony
OF FLOWER
The arrangement of the flower organs
around the axis of a flower is know announcement flowery harmony.
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Actinomorphic flower
(radial harmony)-when a flower can be divided into two equal radial half 8n any
radial aeroplane passing through the centre eg-mustard.
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Zygomorphic flower
(bilateral harmony)-When a flower can be divided into two analogous halves only
in one particular perpendicular aeroplane. (eg-pea)
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Asymmetric flower (
irregular)-When flower can not be divided into two analogous half bay any
perpendicular aeroplane through the centre eg canna.
PARTS OF THE FLOWERS
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Calyx- It's the remotest spiral of
the flower and members are called sepals. Sepals are green Leaf-suchlike
structure that cover the flower in the cub stage
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Corolla- Corolla is the alternate
total of the flower. The individual Leaf member of the corolla is said to be
petals, different shape of corolla are tubular, bell shaped, channel
shapedetc.
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Androciem- It's a third spiral of
Flowers Aries from inner wall of corolla, It's the manly reproductive part
which is composed of stamens.
A stamen correspond of hair
and anther, anther is generally bilobed.
Adhesion of stamens-The stamen
attached to the other corridor of flowery organs similar as petals, sepals,
etc. When a stamen is attached to the petal, also it's called epipetalous.
Cohesion
of stamens- The stamens may be free or united.
When the stamen are free also they're called polyandrous and when stamen are
united in a single pack, also it's called monoadelphous.
Gynoecium- Gynoecium is a womanish reproductive part of the flower
which is composed of one or further carpels. Carpels may be free or
fused.
When carpels are free also they're
said to be apocarpous eg-lotus and rose, and carpels are fused also they said
to be synocarpous. Eg-mustard.
Carpel have three corridor substantially-
Ovary- It's a rudimentary and blown part of the carpel. It's the
lower part of the carpel which bears one or further ovules.
These ovules after fertilisation
develop into seeds. The ovule attached with flattened bumper-suchlike structure
called placenta.
The ovary contain one chamber called
unilocular, if two chamber called bilocular and if three it’s called
trilocular.
Style-The Tube-suchlike structure which connect the smirch to the
overt is called style.
Smirch- Smirch is generally positioned at the tip of the style,
Smirch acts as the open organ for pollen grains during pollination.
PLACENTATION
An ovary has one or further than one
placenta. The arrangement of ovules on the placenta within the ovary. The
different types of placentation arrangements are borderline, axile, parietal,
free central, and rudimentary.
THE
FRUITS
The flowering PLANTS or the
angiosperms are characterised by the presence of a fruit. After fertilisation
the grew or mature ovary is called fruit.
Corridor
OF FRUITS
A fruit substantially correspond of
two corridor videlicet fruits wall and seeds.
Fruit
wall- Fruit wall or pericarp develops
from wall of the ovary. It can be dry or fleshy.
If the pericarp is thick and fleshy
it differentiates into three different layers videlicet.
Epicarp ( external cover), Mesocarp
( middle subcaste), Endocarp ( inmost subcaste).
Still, and if it developed from
other part of flowery PLANTS is called fasle fruits, If a fruit develop
from ovary is called true fruit conformation.
THE
SEEDS
The ovules develop into seeds after
fertilization. A seed is made up of a seed fleece and an embryo.
The embryo is made up of an
embryonal axis and one or two cotyledons. (as in gram and pea).
STRUCTURE
OF DICOTYLEDONS SEED.
Seed fleece-External defensive
covering of the seed is called seed fleece,
which develop from integument of
ovules.
The seed fleece have two subcaste
testa and tegman. The hilum is a scar on the seed fleece through which
developing seed were attached to the fruit.
Above the hilum small severance know
as a micropyle.
Embryo
– Embryo is the most important part
of the seed. The embryo consists of an embryonal axis and two cotyledons.
At the two ends of the embryonal
axis are present the radicle and plumule.
Endosperm- Endosperm is formed as a result of double fertilization. In
some seeds similar as castor, it's a food storing towel.
STRUCTURE
OF MONOCOTYLEDONOUS SEED
In the seed of cereals similar as
sludge the seed fleece is membranous and generally fused with the fruit
wall.
Below the grain covering are present
two structures, endosperm, and embryo.
The endosperm is big and stores
food.
The external covering of the
endosperm separates the embryo by a proteinous subcaste called the aleurone
subcaste.
The endosperm is consists of one
large and guard- shaped cotyledon known as scutellum and a short axis with a
plumule and a radicle.
The plumule and radicle are enclosed
in pods which are called coleoptile andcoleorhiza independently.
PERISPERMIC
SEED
Substantially nucellus is consumed
after fertilization due to immersion of food by the endosperm and embryo.
The nucellus remains patient in the
seed and is called
These seeds are called the
perispermic seeds. Eg Piper nirgun.