Tissues are groups of cells that work together to perform specific functions. There are four main types of animal tissues - epithelial, muscular, connective, and nervous tissue. Epithelial tissue forms protective layers like skin and lines body cavities. It consists of closely packed cells with little extracellular space. Plant tissues include meristematic tissue for growth and permanent tissues like parenchyma, collenchyma, and sclerenchyma. Vascular tissues xylem and phloem transport water and nutrients throughout the plant. Tissues are made of groups of cells that carry out important roles in living organisms.

1. TISSUES

2. Tissues :-
Tissue is a group of cells having similar structure and
function.
In plants and animals groups of cells called tissues carry
out specific functions.
 Eg :- In human beings the cells of the muscular tissue
contract and relax and help in movements.
In plants the cells of the vascular tissue conduct water and
food from one part of the plant to the other.

3. Differences between plant and animal tissues :-
a) Plant tissues :-
 i) Plants do not move from place to place. Most of the cells and tissues
in plants provide mechanical support and strength. So most of the tissues
consists of dead cells because they provide mechanical support and
strength to the plant.
 ii) The growth of plants takes place only in some regions. So plants have
tissues called meristematic tissues which divide and help in growth and
permanent tissues which do not divide.
b) Animal tissues :-
 i) Animals move from place to place and need more energy than plants. So
most cells and tissues in animals are living cells.
 ii) The growth of animals is more uniform so animals do not have separate
dividing and non dividing cells. Animals have organs having specialised
functions. So the organs have specialised tissues.

5. Plant tissues :-
 Plant tissues are of two main types. They are Meristematic
tissues and Permanent tissues.
 i) Meristematic tissues :-
The growth of plants occurs only in certain specific regions.
This is because the dividing tissue, also known as meristematic
tissue.
 The cells of this tissue are very active,
they have dense cytoplasm,
thin cellulose walls and prominent nuclei.
They lack vacuoles.

6. MERISTEMATIC TISSUE
Depending on the region where they are present,
meristematic tissues are of three types.
 They are Apical meristematic tissues, Intercalary
meristematic tissues and Lateral meristematic
tissues.

7. Meristematic tissue :-
Meristematic tissues are found in the growing regions of the
plant like the tips of root, stem and branches. They divide
continuously and help in the growth of the plant. They are of
three types.
 i) Apical meristematic tissues :- are present in the tips of
stems and roots. They help in the growth of stems and roots.
 ii) Lateral meristematic tissues :- are present in in the sides
of stems and roots. They help to increase the girth of the
stems and roots.
iii) Intercalary meristematic tissues :- are present at the base
of leaves and internodes and help in the growth of those
parts.

11. Permanent tissues :-
Permanent tissues are formed from meristematic tissues.
The cells formed by the meristematic tissue, take up a specific
role and lose the ability to divide. As a result, they form a
permanent tissue.
They do not divide and have permanent shape and size.
They differentiate into different types of permanent tissues.
 Permanent tissues are of two main types. They are Simple
permanent tissues and Complex permanent tissues.

12. ii) Permanent tissues :-
are of two types . They are Simple permanent
tissues and Complex permanent tissues.
Simple permanent tissues are of three types.
They are Parenchyma, Collenchyma and
Sclerenchyma.
Complex permanent tissues are of two types.
They are Xylem and phloem.

13. Simple permanent tissues :-
are made up of one type of cells. They are of
three types called Parenchyma, Collenchyma
and Sclerenchyma

14. Parenchyma
consists of :
loosely packed, relatively, unspecialized,
thin walled cells, having more intercellular spaces.
provides support to plants and also stores food.
parenchyma of stems and roots also stores
nutrients and water.

17. CHLORENCHYMA -
Some parenchyma
cells in leaves
contain chloroplast
and prepares food
by photosynthesis.

18. AERENCHYMA - Some
parenchyma cells have
large air cavities which
help the plant to float on
water. Some parenchyma
cells of roots and stem
store water and minerals.

19. Collenchyma :-
consists of living, elongated cells having
less intercellular spaces and irregularly
thickened at the corners.
They give flexibility and allows easy
bending of different parts like stem, leaf
etc. They also give mechanical support to
the plant.

21. Sclerenchyma :-
consists of long, narrow,
dead thick walled cells.
The cell walls contain
lignin a chemical
substance which act like
cement and hardens
them. It gives strength
and hardness to the plant
parts. It makes the plant
hard and stiff.

22. Complex permanent tissues :-
are made up of more than one type of cells. There
are two types of complex tissues.
They are Xylem and Phloem.
They are called vascular or conducting tissues.
Vascular or conductive tissue is a distinctive
feature of the complex plants, one that has made
possible their survival in the terrestrial
environment.

24. Xylem :-
consists of tracheids, vessels, xylem parenchyma
and xylem fibres.
The tracheids and vessels are tubular structures that
help to transport water and minerals vertically from
roots to all part of the plant.
Xylem parenchyma stores food and helps in
sideways conduction of water. The only living cells of
xylem.
 Fibres are supportive in function.
 Tracheids, vessels and xylem fibres are dead cells.

25. Phloem :-
consists of sieve tubes, companion cells, phloem
parenchyma and phloem fibres.
The sieve tubes and companion cells transports
food from leaves to all parts of the plant.
Sieve tubes are tubular structures
Sieve tubes, companion cells and phloem
parenchyma are living cells.
Fibres are the only dead cells in phloem.

26. EPIDERMIS (DERMAL TISSUE)
 is the outermost layer of cells, called epidermis.
 The epidermis is usually made of a single layer of cells.
 In some plants living in very dry habitats, the epidermis may be thicker
since protection against water loss is critical.
 The entire surface of a plant has this outer covering of epidermis. It
protects all the parts of the plant.
 Epidermal cells on the aerial parts of the plant often secrete a waxy, water-
resistant layer on their outer surface. This aids in protection against loss
of water, mechanical injury and invasion by parasitic fungi.
 Since it has a protective role to play, cells of epidermal tissue form a
continuous layer without intercellular spaces.
 Most epidermal cells are relatively flat. Often their outer and side walls are
thicker than the inner wall.

27.  The small pores seen in the
epidermis of the leaf are called
stomata.
 Stomata are enclosed by two
kidney-shaped cells called
guard cells.
 FUNCTIONS OF STOMATA
 They are necessary for
exchanging gases with the
atmosphere.
 Transpiration (loss of water in
the form of water vapour) also
takes place through stomata.

28. Epidermal cells of the roots,
whose function is water
absorption, commonly bear
long hair-like parts that
greatly increase the total
absorptive surface area.

29. In some plants like
desert plants,
epidermis has a
thick waxy coating
of cutin (chemical
substance with
waterproof
quality)on its outer
surface.

30. Another meristematic tissue i.e. cork cambium (or
phellogen) appears in cortical region. It divides and
gives of new cells on both sides. Cork on the outer side
and secondary cortex on the inner. The cells of
secondary cortex are parenchymatous in nature and
often contain chloroplasts.
New cells cut off by cork cambium on outer side are
roughly rectangular in shape and soon become
suberized. They form the cork of the plant. Cork cells
are dead and thick walled and are arranges in few radial
rows. Cork is brownish in colour and is impervious to
water.

32. As plants grow older, the outer protective tissue
undergoes certain changes. A strip of secondary
meristem replaces the epidermis of the stem. Cells on the
outside are cut off from this layer. This forms the several-
layer thick cork or the bark of the tree. Cells of cork are
dead and compactly arranged without intercellular
spaces. They also have a chemical called suberin in their
walls that makes them impervious to gases and water.

34. Animal tissues :-
Animal tissues are of four main types . They are :- Epithelial
tissue, Muscular tissue, Connective tissue and Nervous tissue.
i) Epithelial tissues :- are of different types. They are :-
Squamous, Columnar,
 Cuboidal, Glandular etc.
 ii) Muscular tissues :- are of three types. They are :- Striated,
Unstriated and
 Cardiac.
iii) Connective tissues :- are of different types. They are :- Blood,
Bone,
 Ligaments, Tendons, Cartilage, Areolar, Adipose etc.
iv) Nervous tissue :- consists of nerve cells called neurons.

39. a) Epithelial tissue :-
Epithelial tissue is the covering or protective tissue
in animals. It forms the outer covering like skin,
outer covering of organs, inner lining of blood
vessels, lungs, oesophagus, etc. It protects the
body and controls the movement of materials
between the body and the surroundings and
between the parts of the body. The cells are closely
arranged and have a fibrous basement membrane.

40. The covering or protective tissues in the animal body are
epithelial tissues.
Epithelium covers most organs and cavities within the
body. It also forms a barrier to keep different body
systems separate.
The skin, the lining of the mouth, the lining of blood
vessels, lung alveoli and kidney tubules are all made of
epithelial tissue.
Epithelial tissue cells are tightly packed and form a
continuous sheet.
They have only a small amount of cementing material
between them and almost no intercellular spaces.

41. All epithelium is usually separated from the
underlying tissue by an extracellular fibrous
basement membrane.

45. i) Squamous epithelial tissue :-
consists of a layer of thin flat cells. It is
present in the linings of blood vessels,
lungs, mouth, oesophagus etc.
Squamous epithelial tissue are divided into
simple epithelial tissue and stratified epithelial
tissue.

47.  Common Characteristics
1) Individual cells are closely attached to
each other at their margins to form tight
sheets
2) No extra-cellular matrix
3) No vascularization

48. Functions
1) Protection: covers body and lines all body
cavities; provides a protective shield for underlying
tissues
(e.g. epidermis)
2) Absorption: in some parts of the body it takes in
certain materials (e.g. digestive tract)
3) Secretion: in some parts of the body epi. tissue is
specialized to secrete certain products
E.g. small intestine: some cells are specialized to
secrete mucus

49. SIMPLE SQUAMOUS EPITHELIUM
Simple squamous epithelial cells are extremely thin
and flat and form a delicate lining.
Functions:
Makes a very thin membrane that is good for the
passage of molecules (diffusion)
Found:
lines arteries and veins
capillaries
alveoli of lungs

51. The skin has several layers of epithelial cells.
This tissue is called Stratified squamous
tissue.

Many layers of flat cells
Two types:
Keratinized: waterproof
Unkeratinized: not waterproof
Found
Keratinized:
skin
scalp
bottom of feet.
 Unkeratinized
mouth
lining of nose

54. ii) Columnar epithelial tissue :-
consists of tall pillar like cells. It is present
in the walls of the intestine.
The columnar epithelial tissue in the
respiratory tract has hair like projections
called cilia. This tissue is called Ciliated
columnar epithelial tissue.

56. iii) Cuboidal epithelial tissue :-
Consists of cube shaped cells having a
basement membrane.
It forms the lining of kidney, tubules and
ducts of salivary glands and provide
mechanical support.

59. Simple Columnar Epithelium

One layer of long thin cells
This columnar (meaning ‘pillar-like’)
epithelium facilitates movement
across the epithelial barrier.

Functions:
Absorption and secretion (with
microvilli)
Found
small intestine
stomach
large intestine
glands

60. Ciliated Columnar
epithelial tissue
In the respiratory tract, the
columnar epithelial tissue
also has cilia, which are
hair-like projections on the
outer surfaces of epithelial
cells. These cilia can move,
and their movement
pushes the mucus forward
to clear it. This type of
epithelium is ciliated
columnar epithelium.

61. iv) Glandular epithelial tissue :-
Epithelial cells often acquire
additional specialisation as gland
cells, which can secrete
substances at the epithelial
surface.
Sometimes epithelial tissue folds
inwards and forms a multicellular
gland. This tissue is called
Glandular epithelial tissue.

62. b) Muscular tissue :-
 Connective tissue helps in the movements of the
body. It consists of elongated cells called muscle
fibres. It contains a protein called contractile
protein which contracts and relaxes and helps in
movements.
Muscles which can move under our will are called
voluntary muscles. Muscles which do not move
under our will are called involuntary muscles.

63. i) Striated muscles :-
are voluntary muscles because they can be
controlled (are under our will)
having light and dark striations.
The cells are long, cylindrical and are
multinucleated.
They are also called skeletal muscles because
they are attached to bones.
They help in voluntary movements of the body.

64. ii) Unstriated muscles ( Smooth
muscles) :-
are involuntary muscles having no
striations.
The cells are long and spindle shaped and
are uninucleated.
They are present in alimentary canal, blood
vessels, bronchi of lungs, iris of eye etc.
They help in involuntary movements.
They are not attached to skeletal system.

65. iii) Cardiac muscles :-
are involuntary muscles having faint
striations.
The cells are long, cylindrical, branched
and multinucleated.
They are present in the heart and helps in
the contraction and relaxation of the heart.

68. c) Connective tissue :-
Connective tissue connects and joins the
different parts of the body together.
The cells of the connective tissue are
loosely packed and the space between the
cells are filled with a jelly like matrix.

69. i) Blood :-
Blood contains a fluid
matrix called plasma
which contains red
blood cells (RBC), white
blood cells (WBC) and
platelets.
The blood transports
gases, digested food,
hormones, waste
materials etc.

70. ii) Bone :- is a hard and strong
tissue. It consists of
cells which are
embedded in a hard
matrix containing
calcium and
phosphorus
compounds.
Bone forms the
framework of the body
and supports the body
and the main organs.

71. iii) Ligaments :- are
flexible tissues which
joins bones together and
helps in movements.
iv) Tendons :- are fibrous
tissues which joins
muscles to bones and
helps in movements.

72. v) Areolar tissues :-
fills the space
between skin
and muscles,
inside the
organs, around
blood vessels
etc. It helps to
repair the
tissues

73. vi) Adipose tissue :-
is found below the
skin and between
internal organs. It
contains fats and
helps to store fats.

74. d) Nervous tissue :-
Nervous tissue helps to carry messages
from one part of the body to the other and
responds to stimuli. It is found in the brain,
spinal cord and nerves. It consists of nerve
cells called neurons.

75. Neuron (Nerve cell) :-
has a cell body containing a nucleus and
cytoplasm. It has hair like structures called
dendrites and a long part called axon having
nerve endings. The axon has a protective
covering called myelin sheath. The neurons are
joined together to form nerve fibres.
The junction between two neurons is called
synapse.