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• Meristematic tissues are composed of cells
that divide continuously.
• The cells are spherical, oval, polygonal or
• The cell wall is thin and made up of cellulose
• The cells are closely arranged without inter-
• Cytoplasm is abundant and nuclei are large
• Vacuoles are absent and if present, very few
Classification of meristems
• 1. Apical meristem
Position: At the root tip and shoot tip.
Function: To increase in length of the axis.
• 2. Lateral meristem
Position: On the lateral side of stem and root.
Function: To increase in diameter of plant.
• 3. Intercalary meristem
Position:At the base of the leaf/internodes/ leaf.
Function:To increase the length of the plant or its organs.
Function of the merestematic
The main function of meristematic tissue
is to continuously form a number of new
cells and help in growth
• Forms permanent tissues
• When the cells formed by meristematic
tissue take up a specific role and lose
the ability to divide. As a result, they
form a permanent tissue. This process
of taking up a permanent shape, size,
and a function is called differentiation.
Cells of meristematic tissue
differentiate to form different types of
Simple permanent tissue
• A simple tissue is made up of one type
of cells that form a homogeneous or
uniform mass. Simple plant tissues
include parenchyma, collenchyma and
• Cells are isodiametric i.e.
equally expanded on all
• They may be oval, round,
polygonal or elongated.
• Nucleus is present and
• The cell walls are thin and
made of cellulose.
• Cytoplasm is dense with a
single large vacuole.
• Intercellular spaces may be
• May contain chlorophyll.
Parenchyma which contain
chlorophyll are called
• Found in the cortex
of root, ground
tissue in stems and
mesophyll of leaves.
• Store and assimilate food
• Give mechanical strength by
• Prepare food if chlorophyll is present
• Store waste products like tanin, gum,
crystals and resins
• The cells are elongated and are
circular, oval or polygonal in
• Cell wall is unevenly thickened
with cellulose at the corners
against the intercellular
• Nucleus is present and hence
the tissue is living.
• Vacuoles are small.
• Intercellular spaces are
• If they contain chlorophyll they
are known as chlorenchyma.
• Found under the
skin i.e. below
the epidermis in
• Provide mechanical support to the stem.
• Being extensible, these cells readily adapt
themselves to the rapid elongation of the
• The cells are long, narrow,
thick and lignified, usually
pointed at both ends.
• The cell wall is evenly
thickened with lignin and
sometimes is so thick that the
cell cavity or lumen is absent.
• Nucleus is absent and hence
the tissue is made up of dead
• They have simple often,
oblique pits in the walls.
• The middle lamella i.e. the
wall between adjacent cells is
• Found abundantly in
stems of plants like hemp,
jute and coconut.
• It is present in stems,
around vascular plants , in
the leaves, hard covering
• Gives mechanical
support to the plant
by giving rigidity,
elasticity to the
The sclerenchyma cells are
usually elongated, with tapering
ends. Such cells are commonly
described as sclerenchyma fibres
cells are shorter and irregular in
shape. Such cells are commonly
described as sclereids or stone
• Sclereids ( Also known as stone
cells or sclerotic cells)
• Occurrence : Most common in fruits
• A) Structure
• Cells are short, isodiametric, spherical,
oval, t shaped or cylindrical in shape.
• Usually have thick lignified secondary
• Occur single or in loose groups.
• B) Functions
Protects the plant from stress and
strains from environment.
• Provide mechanical strength and
• Provide grittiness to the pulp of fruits.
• These are made of more than one
type of cells which combine together
to work as a unit.
• They transport water and food
material to various parts of the plant
• They are of two types- xylem and
This complex tissue helps in the
transport of water and soluble mineral
nutrients from the roots to all the parts
of the plant body. It also helps in
replacing the water lost during
transpiration and photosynthesis.
This tissue is found in the
vascular plants. Its
function is to transport
sugars and other food
materials from the leaves
to the rest of the parts of
the plant body.
Xylem and Phloem together
form the vascular bundle.
Components of phloem
• Sieve tube
• Companion cell
• Phloem fibre
• Xylem and
• Although our body parts are diverse in both structure and
function, they are all constructed from four basic tissue
• 1. Epithelial tissue: Covers the body, lines the cavities
of the body and composes the glands.
• 2. Connective tissue: Connects and supports the
structures of the body, providing structural support and
binding organs together.
• 3. Muscular tissue: Has the unique capability to
contract or shorten, provides movement and heat for the
• 4. Nervous tissue: Composed of specialized cells that
respond to the environment by detecting, processing and
The covering or
in the animal body
are called epithelial
Characters of epithelial tissues
• 1. cells are tightly
• 2.epethelium is
from the underlying
tissue by an extra
• Different epithelia show differing structures that correlate with their
• For example, in cells lining blood vessels or lung alveoli, where
transportation of substances occurs through a selectively permeable
surface, there is a simple flat kind of epithelium. This is called the
simple squamosal epethelium
• Where absorption and secretion occur, as in the inner lining of the
intestine, tall epithelial cells are present. This columnar (meaning
‘pillar-like’) epithelium facilitates movement across the epithelial
• Cuboidal epithelium (with cube-shaped cells) forms the lining of
kidney tubules and ducts of salivary glands, where it provides
CHARECTERS OF SQUAMOSAL
Cells are thin & flat
& form a delicate
Cells are like tiles
on the floor
LOCATION OF CUBOIDAL
1. LINING OF KIDNEY TUBULE
2. LINING OF DUCTS OF
It has tall epithelial cells. Cells may
have celia or without celia
LOCATION OF COLUMNAR EPETHELIUM
1.Innerlining of the respiratory tract
Celia pushes the mucus
forward to clear the
2. Interlining of the oviduct
Celia push the
The skin, which protects the body, is also made of
squamous epithelium. Skin epithelial cells are
arranged in many layers to prevent wear and tear.
Since they are arranged in a pattern of layers, the
epithelium is called stratified squamous epithelium.
Blood has a fluid (liquid) matrix called
plasma, in which red blood cells
(RBCs), white blood cells (WBCs) and
platelets are suspended.
The plasma contains proteins,
salts and hormones.
Blood flows and transports gases,
digested food, hormones and waste
materials to different parts of the
• It is a strong and
• Bone cells are embedded
in a hard matrix that is
composed of calcium and
• Bone cells are called
Functions of bone
• It forms the
• It also anchors
the muscles and
main organs of
• It has widely spaced cells.
• The solid matrix is composed of
proteins and sugars.
• Cells are called chondrocytes
1. Between the bones at the joints.It
smoothens bone surfaces at joints
2. in the nose, ear, trachea and
• It consists of a jelly-like
matrix in which there
are several kinds of
cells and interlacing
bundles of fibers.
• The fibers are of two
kinds, white and yellow.
The white fibers are
very resistant to
stretching but the
yellow fibers can be
stretched and are called
yellow elastic fibers.
• Some of the cells are
able to consume and
destroy germs and so
play a valuable part in
the body's defensive
system against disease.
• Areolar connective
tissue is found
• the skin and
and nerves and in
the bone marrow.
• It fills the space
inside the organs,
• organs and helps in
repair of tissues.
• Adipose Tissue is a loose
fibrous connective tissue
packed with many cells (called
"adipocytes") that are
specialized for storage of
triglycerides more commonly
referred to as "fats".
• Each adipocyte cell is filled
with a single large droplet of
triglyceride (fat). As this
occupies most of the volume of
the cell, its cytoplasm,
nucleus, and other
components are pushed
towards the edges of the cell -
which is bounded by the
Adipose tissue is found below
the skin and between internal
Adipose tissue -location
FUNTIONS OF ADIPOSE TISSUE
• 1. Storage of fat
• 2. Acts as insulator (prevents the heat
loss from the body)
• Muscular tissue consists of
elongated cells,also called
muscle fibres. This tissue is
responsible for movement
in our body.
• Muscles contain special
proteins called contractile
proteins, which contract
and relax to cause
Characters of striated muscles
• 1. Cylindrical,
• 2. Striations
• 3. Many nuclei
• 4. Attached to bones
• 5. Voluntory
• All cells possess the ability to respond to
However, cells of the nervous tissue
are highly specialised for being stimulated
and then transmitting the stimulus very
rapidly from one place to another within the
• The brain, spinal cord and nerves are
all composed of the nervous tissue. The cells
of this tissue are called nerve cells or neurons.
Structure of the neuron
• Cell bodyCell body – main part– main part
• DendriteDendrite – receives action– receives action
potential (stimulation) frompotential (stimulation) from
other neuronsother neurons
• AxonAxon – branches from cell– branches from cell
body, where the actionbody, where the action
potential occurspotential occurs
• Axon terminalAxon terminal – end of an– end of an
• Myelin sheathMyelin sheath – lipid layer– lipid layer
for protection over neuronsfor protection over neurons
• Nodes of RanvierNodes of Ranvier – gaps in– gaps in
myelin sheathmyelin sheath