2. Introduction
A cellular organization between a single
cell and a complete organism is
controlled by the tissue.
They are the collection of similar cells,
with specific function.
A collection of tissue gives rise to an
organ.
A tissue is simple, which may be single
celled type or a complex cell type.
3. Plant Tissue
A group of cells
dividing, to give
rise to large
number of cell,
which is
collectively
referred as
tissues.
They are
structurally and
4. Plant Tissue System
Plants do have a higher
level of structure called
plant tissue systems.
A plant tissue system
can be defined as a
functional unit, which
connects all organs of a
plant.
Like animal tissue
system, plant tissue
system is also grouped
into various tissues
based on their
functions.
7. Dermal Tissues
They are the tissues, which covers the
external part of the herbaceous plants.
They are composed of epidermal cells,
which secrete the waxy cuticle.
Waxy cuticles are responsible for
protecting plants against water loss.
Consists of epidermis and periderm.
8. Epidermis
They are the outermost layer of the primary plant body,
which covers roots, stems, leaves, floral parts, fruits and
seeds.
They are one layer thick with cuticle.
They are composed mostly of unspecialized cells-
parenchyma and sclerenchyma.
They include trichomes, stomata, buIIiform ceIIs, etc.
9. Periderm
They are the outermost
layer of stems and roots of
woody plants such as trees.
They are also called as
barks.
They replace epidermis in
plants that undergo
secondary growth.
They are multilayered
structures.
They include cork cells,
which are nonliving cells
that cover the outside of
stems and roots.
The periderm protects the
plant from injuries,
pathogens and also from
excessive water
10. Ground Tissues
They synthesize the organic
compounds and support the plants by
storing the produced products.
They are composed of parenchyma
cells and also include collenchyma
and sclerenchyma cells.
11. Parenchyma
They are the general cells of plants,
which are circular in shape and have
very thin wall.
They are present in all plant cells.
They have very large vacuoles and
are frequently found in all roots, stem,
leaves and in fruits
Parenchyma cells help in synthesizing
and storage of synthesized food
products.
Parenchyma cells also controls plant's
metabolism like photosynthesis,
respiration, protein synthesis.
They also play a vital role in wound
healing and regeneration of plants.
12. Collenchyma
Collenchymas are specialized parenchyma tissue, which are found in all
green parts.
Collenchyma cells are elongated with unevenly thickened walls.
They are alive during the cell maturity.
Collenchyma cells controls the functions of young plants.
A collenchyma cell provides a support to plants by not restraining growth,
which is caused due to their absence of secondary walls and hardening
agent in their primary walls.
13. Sclerenchyma
They are rigid, non-living cells.
They have thick, lignified secondary walls and
lack protoplasts at maturity.
They provide strength
A sclerenchyma cell also provides a support to
plants with the help of hardening agent present
in their cells.
Sclerenchyma cells are of two types:
1. Sclereids: short, irregular in shape and have
thick, lignified secondary walls
Fibers: are long, slender and are arranged in
threads.
15. Vascular Tissues
They are specialized cells with transport of
water, hormone and minerals throughout
the plant.
They contain transfer cells, fibers in
addition to xylem, phloem, parenchyma,
cambium and other conducting cells.
They are located in the veins of the
leaves.
16. Xylem
The term xylem•is derived
from the Greek word
meaning wood•.
are dead with hollow cells,
which consist of only cell
wall.
play a vital role in
transporting water and
dissolved nutrients from the
roots to all parts of a plant.
transport the nutrients in
the upward direction .i.e.
from the root to the stem,
leaves and flower.
also called as water-
conducting cells.
17. Phloem
The term phloem is derived
from the Greek word
meaning bark.
are live cells, which lack
nucleus and other
organelles.
transport dissolved organic
food materials (sugars) from
the leaves to all parts of a
plant.
transport the nutrients in the
downward direction .i.e.
from the leaves to the
different parts of the plant.
also called as sugar-
conducting cells.
18.
19. Meristematic Tissues
group of cells, which
have the ability to
divide.
consists of small,
cubodial densely
packed cells, which
keeps on dividing to
form new cells.
capable of stretching,
enlarging and
differentiate into other
types of tissues as
they mature.
give rise to permanent
tissues.
20. Characteristics of Meristematic
tissues
have very small cells with thin cell walls.
cells have large nuclei.
cells have very small vacuoles and they lack
intercellular spaces.
remain young forever and divide actively
throughout the life of the plant.
In plants, these tissues are found in the -Tips of
roots, stems, nodes of stems, buds, in between
the xylem and phloem, under the epidermis of
dicotyledonous plants and also producing branch
roots.
21. Kinds of Meristematic Tissues
Apical meristems : They are
found at the tip of stems and
roots. During the cell division,
this meristem helps in cellular
enlargement and also it
influence the shapes of the
mature plants.
Lateral meristems : They are
found along the sides of roots
and stems .They play a vital
role in increasing the width or
diameter of stems and roots.
Intercallary meristems : They
are found at the bases of
young leaves and
internodes. They are mainly
responsible for further
lengthening of stems and
leaves.
22. Permanent Tissues
The tissues, which are derived from the Meristematic
tissues
They are the tissues, which have lost their ability to
divide as they have attained their mature form.
Kinds of Permanent Tissues
Simple permanent tissue: are the tissues, which are
similar in function and are called as simple because
they are composed of similar types of cells, which
have common origin and function.
Complex permanent tissue: are the tissues, which are
composed of two or more types of cells but contribute
to a common function are called complex tissues.