This is about plant tissue

1. Plant Anatomy
1
Presenter : Dr. Manoj Das

2. Plant anatomy { Gk . Ana =after +
tome=to cut} deals with the study of
internal structure study of plant . Internally
plant is composed of various types of
tissue . The tissue was termed by N.
Grew who is considered as father of plant
anatomy.
Histology-It is the branch of life science
which deals with study of tissue
Tissue-It is a group of similar and
dissimilar cells having same origin
structure and functions

3. Types of tissue
Depending upon the growing nature of
tissue , it has two types:
A . Meristemtic tissue
B. Permanent tissues
A. Meristemtic tissue- Meristem {Gk.
Meristos = divisible} tissue is
defined as a mass of young
immature and undifferentiated cells,
which have the capacity of
continuous division.

4. Characters of meristem
1. Meristematic cells are living and thin
walled.
2. They are compactly arranged without
intercellular spaces.
3. They have densely cytoplasm and
prominent nucleus.
4. The vacuoles are either small or
absent
5. Endoplasmic reticulum and
mitochondria are not fully developed
6. They posses plastid in proplastidial

5. Types of meristem
I. Meristem are classified as on the basis of
plane of division-It includes
I . Mass meristem –The cells of plate
meristem divide in almost all the planes.
Hence , irregular shaped endosperm is
formed
2.Plate meristem-The cells of plate
meristem divide in anticlinal plane and form
plate-like structure. It contributes to the
formation of uniseriate epidermis and
multiseriates blade of the leaf.

6. 3. Rib meristem- Cells of this meristem
divide right angle to the longitudinal axis
to form cortex and pith in roots and
stems
II. On the basis of development ,
meristems are as
1. Primary meristem- It originates from
the pro meristem during the embryonic
condition and occurs at the tip of root
stem etc.
2. Secondary meristem- It arises from

7. III. On the basis of functions, meristems
are as
1. Proto derm -This is the outermost
layer that forms the epidermis.
2. Ground tissue- Cells of this region are
large and contributes to the formation
of hypodermis cortex and endodermis.
3. Procambium – The cells of this region
are vertically elongated . They
produce primary vascular tissues.

8. IV . On the basis of position, meristems are
as
1. Apical meristem- These are situated at
the tips of the root and the stem . Plants
elongated and increase in height as a result
of division in the meristem
2.Lateral meristem- These are meristem
are present along the side of the stem .
Due to its lateral position it is known as
lateral meristem . The vascular cambium
and cork cambium are the two examples of
lateral meristem. It increases the diameter

10. 3.Intercalary meristem-It is located away
from the apical meristem between the two
differentiated regions. It occurs in the
leaves and inter nodes of many
monocotyledons, pedicels below the node
in Mentha etc. In fact grass stem
elongates due to the activity of intercalary
meristem.

11. Apical meristem
The apical meristem occurs at the apices
of the main and lateral branches of
shoots and roots. The activity of apical
meristem adds to the length of plants or
its parts.
Several theories have been put forward
to explain the organization of the shoot
apex. But tunica corpus theory is widely
accepted. This theory was proposed by
Schimdt. This theory is applicable only to

12. two zones
a. Tunica- It consists of one or more
peripheral layers of cells. These
cells divide mostly anticlinal
divisions and contributes the surface
expansion of the shoot apex. If the
tunica is more than one layered, the
outermost layer forms the epidermis
and the remaining layer contributes
to the formation of leaf primodia and
some part of cortical region.

14. b. Corpus- It is central massive region
surrounded externally by tunica layer.
Cells of corpus divide almost all
planes and give rise to remaining part
of the cortex, vascular tissues and
pith.

15. B. Permanent tissue
It may be defined as a group of cells
which have lost the capacity of division. It
includes
1. Simple permanent tissues- Tissues
composed of only one type of cells
are called as simple permanent
tissues. They are as-
a. Parenchyma-
Distribution- It is present in members of
bryophytes to tracheophytes. It occurs in

16. Characters
i. Parenchyma are thin walled living
cells.
ii. The cell wall is made of cellulose,
hemicellulose and pectin.
iii. Cells are isodiametric.
iv. Intercellular spaces are present.
Type
The parenchyma is as
i. Chlorenchyma- These
parenchymatous cells have abundant

17. x. Palisade parenchyma- It is a type
of chlorenchyma where the cells are
elongated or rod like in structure.
x. Spongy parenchyma- It is a also
type of chlorenchyma where the cells
are irregular in shape.
Both palisade and spongy
parenchyma have well defined inter
cellular spaces and occur in
mesophyll of leaves.

18. ii. Aerenchyma- A parenchyma with well
developed intercellular spaces which
formed a connected system throughout
the entire plant body known as
aerenchyma and occurs in submerged
plants like Hydrilla ,Trapa Nymphaea
etc.
iii. Prosenchyma- A parenchymatous
cells become long and taper at one end
are called as prosenchyma and occurs
in pericycle of some plants.

19. Functions-
i. Parenchyma becomes meristematic
during wound healing, formation of
adventitious roots, grafting etc.
ii. Important physiological phenomena like
photosynthesis, transpiration respiration
etc. are performed by parenchyma.
iii. The parenchyma helps in storage of food
materials and water
iv. The aerenchyma helps hydrophytes to
float due to air present in the intercellular
spaces as air chambers formed by them.

21. Collenchyma
Distribution- In herbaceous dicot stems,
the collenchyma is generally present below
the epidermis. It is found in the petiole,
lamina and bundle sheath of the leaves. It
is absent in underground stems and roots.
It is also absent in stem and leaves of
monocots.
Characters
i. It is a mechanical tissue that consists of
living cells.
ii. The cell wall is thickened due to the

22. ii. Collenchyma may or may not have
intercellular spaces
iii. Intercellular spaces are absent.
iv. Pits are absent.
Type
On the basis of pattern of deposition of pectin,
the collenchyma is as
a. Angular collenchyma- In this type of
collenchyma the pectin is mainly deposited
at the corners or angles of cells and occurs
in members of Cucurbitaceae, Datura
,Cannabis ,Vitis etc.

23. the tangential wall of cells and occurs in
stem of Helianthus, Eupatorium etc.
c. Lacunar collenchyma- It contains pectin
deposition on walls around the intercellular
spaces and occurs in Calotropis, aerial
roots of Monstera etc.
Functions-
i. It provides mechanical support to the
plant body.
ii. It helps in the photosynthesis if
chloroplasts are present
iii. It prevents from tearing of leaves.

25. Sclerenchyma
Distribution- It is widely distributed in
trachaeophytes. It occurs in hypodermis of
monocot stem peicycle xylem phloem etc.
Characters-
i. Cells are long or short, narrow thick walled
and highly lignified.
ii. Cells are dead and do not perform
metabolic activities.
iii. The intercellular spaces are absent,
iv. Pits are present.
v. The cell wall is thickened due to the

26. • Type
• The Sclerenchyma are of two types-
• 1. Sclereid- The short and irregular
sclerenchyma is called as sclereid. The cell
wall is highly lignified thick having narrow
lumen.
• On the basis of shape, sclereids are as-
• i. Brachysclereids- They are usually
isodiametric in shape and occur in pulp of pear.
• Ii. Osteosclereids- They are bone like in
structure and occur in seed coat of many
dicots.

27. • Iv. Trichosclereids- They are hair like in strucure
and occurs in aerial roots of Monstera.
• V. Macrosclereids- They are elongated rod like in
structure and occur in seed coat of pulses.
• 2. Sclerenchymatous fibers- They are many
times longer than broad. Most of the fibers are
elongated and their ends are pointed. They are
as-
• a. Xylary fibers- These fibers are associated with
xylem of stem and roots and occur in Cannabis
sativa.
• b. Extra xylary fibers- These include all fibers
which occur in the tissues other than the xylem.

28. • Cotton fibers, mesocarp fibers of coconut.
• Ii. Bast fibers- These fibers are associated
with phloem and pericycle and occur in Linum
utitatissium.
• Functions-
• i. It provides mechanical support to the plant
body.
• Ii. It reduces the rate of transpiration.
• Ii It protects seeds and fruits from dry season.
• Iv. It helps in dispersal of seeds.