Tissues Class 9 Biology Notes – CBSE & ICSE | Complete Chapter Notes

By Shivani Gupta

September 23, 2026

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Tissues Class 9 Biology Notes – CBSE & ICSE | Complete Chapter Notes

1. What is a Tissue?

A tissue is a group of similar cells that work together to perform a specific function.

Why are tissues needed?

In multicellular organisms, different cells perform different functions. This division of labour makes the body more efficient.

Example:

Muscle tissue → movement
Nervous tissue → transmission of messages
Xylem → transport of water in plants

Plant Tissues vs Animal Tissues

Plant Tissues	Animal Tissues
Plants are generally stationary.	Animals show active movement.
Many tissues provide mechanical support.	Many tissues are involved in movement and coordination.
Growth occurs mainly in specific regions.	Growth generally occurs throughout the body during development.
Supporting tissues often contain dead cells.	Most functional tissues contain living cells.

PART A – PLANT TISSUES

Plant tissues are broadly divided into:

1. Meristematic Tissue
2. Permanent Tissue

2. Meristematic Tissue

Meristematic tissue consists of actively dividing cells. It is responsible for the growth of plants.

Main characteristics

Cells divide continuously.
Cells are small and closely packed.
Cell walls are thin.
Cytoplasm is dense.
Nucleus is prominent.
Vacuoles are absent or very small.
There are very few intercellular spaces.

Types of Meristematic Tissue

A. Apical Meristem

Location: Tips of roots and shoots.

Function: Increases the length of the plant.

Remember:
Apical → Apex → Length

B. Intercalary Meristem

Location: At the base of leaves or internodes, especially in grasses.

Function: Helps in increasing the length of internodes and allows rapid regrowth after grazing or cutting.

Example: Grass.

C. Lateral Meristem

Location: Along the sides of stems and roots.

Function: Increases the girth/thickness of the plant.

Example: Vascular cambium and cork cambium.

Remember:
Lateral → Lateral growth → Girth

Important comparison

Meristem	Location	Main function
Apical	Root and shoot tips	Increase in length
Intercalary	Base of leaves/internodes	Increase in length
Lateral	Sides of stem/root	Increase in girth

3. Permanent Tissue

Permanent tissues are formed from meristematic cells that lose their ability to divide and become specialised for particular functions.

This process is called differentiation.

Permanent tissues are broadly classified into:

Simple Permanent Tissue

Made up of one type of cell.

Parenchyma
Collenchyma
Sclerenchyma

Complex Permanent Tissue

Made up of more than one type of cell working together.

Xylem
Phloem

4. Simple Permanent Tissues

A. Parenchyma

Parenchyma consists of living, thin-walled cells.

Functions

Storage of food
Photosynthesis when chloroplasts are present
Repair and regeneration
Packing tissue

Special forms

Chlorenchyma: Parenchyma containing chloroplasts; performs photosynthesis.

Aerenchyma: Parenchyma containing large air spaces; provides buoyancy to aquatic plants.

Example: Aquatic plants such as water hyacinth.

Key point

Parenchyma = Living + Storage

5. Collenchyma

Collenchyma consists of living cells with unevenly thickened cell walls, particularly at the corners.

Location

Below the epidermis of young stems
Leaf stalks
Leaf veins

Functions

Provides mechanical support.
Provides flexibility.
Allows bending of plant parts without breaking.

Example: Leaf stalk of celery.

Key point

Collenchyma = Support + Flexibility

6. Sclerenchyma

Sclerenchyma consists mainly of dead cells with thick, lignified walls.

Functions

Provides mechanical strength.
Provides rigidity and protection.

Examples

Coconut husk
Seed coats
Nut shells
Fibres around vascular tissues

Types

Fibres
Sclereids

Key point:
Sclerenchyma = Dead + Thick + Strong

7. Comparison of Simple Permanent Tissues

Feature	Parenchyma	Collenchyma	Sclerenchyma
Cells	Living	Living	Dead at maturity
Cell wall	Thin	Unevenly thickened	Very thick and lignified
Main function	Storage	Support & flexibility	Strength
Intercellular spaces	Usually present	Very little	Usually absent
Special feature	May contain chloroplasts	Thickening at corners	Lignin present

8. Protective Tissues

Protective tissues cover and protect the plant body.

A. Epidermis

The epidermis is the outermost layer of cells covering plant parts.

Functions

Protects the plant from injury.
Reduces water loss.
Protects against infection.
Helps in gas exchange through stomata.

Cuticle

The epidermis of aerial parts often has a waxy layer called the cuticle.

It helps reduce water loss.

9. Stomata

Stomata are tiny pores mainly present on the epidermis of leaves.

Each stoma is surrounded by guard cells.

Functions

Exchange of gases
Transpiration

Important terms

Stoma: Opening/pore
Guard cells: Control opening and closing of the stoma

Key concept

When guard cells become turgid, the stomatal pore generally opens.
When they lose water and become flaccid, the pore generally closes.

10. Cork

Cork forms a protective covering in older stems.

The cells are generally dead and compactly arranged.

They contain suberin, which makes them impermeable to water and gases.

Function

Prevents water loss
Protects against mechanical injury
Provides insulation

11. Complex Permanent Tissues

Complex tissues consist of different types of cells working together.

The two major complex tissues are:

Xylem

Transports water and minerals.

Phloem

Transports food.

12. Xylem

Xylem mainly transports water and minerals from the roots to other parts of the plant.

Components of Xylem

Tracheids
Vessels
Xylem fibres
Xylem parenchyma

Important point

Xylem parenchyma is living.
Most other xylem elements are dead at maturity.

Functions

Transport of water and minerals
Mechanical support

13. Phloem

Phloem transports food prepared by photosynthesis from leaves to other parts of the plant.

Components

Sieve tubes
Companion cells
Phloem parenchyma
Phloem fibres

Important point

Most phloem components are living, except phloem fibres, which are dead at maturity.

Key concept

Xylem → Water + Minerals
Phloem → Food

14. Xylem vs Phloem

Xylem	Phloem
Transports water and minerals	Transports food
Mainly upward movement from roots	Food can move in different directions depending on source and sink
Mostly dead cells	Mostly living cells
Provides mechanical support	Mainly conducts organic food
Components include vessels and tracheids	Components include sieve tubes and companion cells

PART B – ANIMAL TISSUES

Animal tissues are broadly classified into:

Epithelial tissue
Connective tissue
Muscular tissue
Nervous tissue

15. Epithelial Tissue

Epithelial tissue forms the covering or lining of body surfaces and organs.

Functions

Protection
Absorption
Secretion
Excretion
Exchange of substances

16. Types of Epithelial Tissue

A. Squamous Epithelium

Made of thin, flat cells.

Location

Alveoli of lungs
Lining of blood vessels

Function

Allows rapid diffusion and exchange of substances.

Shape: Flat

B. Stratified Squamous Epithelium

Consists of multiple layers of cells.

Location

Skin

Function

Provides protection against mechanical damage.

Remember:
Stratified = Many layers = Protection

C. Cuboidal Epithelium

Cells are approximately cube-shaped.

Location

Kidney tubules
Ducts of glands

Functions

Absorption
Secretion

D. Columnar Epithelium

Cells are tall and column-shaped.

Location

Lining of intestine

Functions

Absorption
Secretion

E. Ciliated Epithelium

Cells have cilia on their free surface.

Location

Respiratory tract
Oviducts/fallopian tubes

Function

Moves materials in a particular direction.

F. Glandular Epithelium

Specialised epithelial cells involved in secretion.

Function

Secretion of substances such as enzymes, mucus and hormones.

17. Connective Tissue

Connective tissue connects, supports, binds and protects different parts of the body.

It generally contains:

Cells
Protein fibres
Ground substance/matrix

Major types

Areolar tissue
Adipose tissue
Tendon
Ligament
Cartilage
Bone
Blood

18. Areolar Tissue

Areolar tissue is a loose connective tissue.

Location

Between skin and muscles
Around blood vessels and nerves
Between internal organs

Functions

Supports internal organs
Fills spaces
Helps in tissue repair

19. Adipose Tissue

Adipose tissue stores fat.

Location

Under the skin
Around internal organs

Functions

Energy storage
Insulation
Protection of organs

20. Tendon

A tendon connects muscle to bone.

It is strong and has great tensile strength.

Remember:

Tendon → Muscle → Bone

21. Ligament

A ligament connects bone to bone at a joint.

It is strong but also flexible.

Remember:

Ligament → Bone → Bone

22. Cartilage

Cartilage is a flexible connective tissue.

Location

Nose
Ear
Trachea
Ends of bones at joints

Functions

Provides support
Provides flexibility
Reduces friction at joints

23. Bone

Bone is a hard connective tissue.

Functions

Supports the body
Protects internal organs
Provides attachment to muscles
Helps in movement
Bone marrow is involved in blood cell formation

24. Blood

Blood is a fluid connective tissue.

Components

Plasma
Red blood cells
White blood cells
Platelets

Functions

Transport of oxygen
Transport of nutrients
Transport of hormones
Defence against disease
Blood clotting

Important concept

Blood is called connective tissue because its cells are suspended in a fluid matrix called plasma.

25. Muscular Tissue

Muscular tissue is specialised for contraction and movement.

There are three major types:

Striated/Skeletal muscle
Smooth/Unstriated muscle
Cardiac muscle

26. Striated Muscle

Also called skeletal muscle.

Features

Long, cylindrical fibres
Unbranched
Many nuclei
Alternating light and dark bands
Voluntary control

Location

Attached to bones.

Function

Movement of the skeleton.

27. Smooth Muscle

Also called unstriated muscle.

Features

Spindle-shaped cells
Single nucleus
No striations
Involuntary

Location

Intestine
Stomach
Blood vessels
Urinary bladder

Function

Movement of substances through internal organs.

28. Cardiac Muscle

Found only in the heart.

Features

Striated
Branched
Usually one nucleus
Involuntary
Rhythmic contraction

Function

Pumps blood throughout the body.

Special feature

Cardiac muscle cells are connected by intercalated discs, which help coordinate contraction.

29. Comparison of Muscular Tissues

Feature	Striated	Smooth	Cardiac
Striations	Present	Absent	Present
Shape	Long, cylindrical	Spindle-shaped	Branched
Control	Voluntary	Involuntary	Involuntary
Nuclei	Many	One	Usually one
Location	Attached to bones	Internal organs	Heart
Main function	Body movement	Movement of substances	Pumping blood

30. Nervous Tissue

Nervous tissue is specialised for receiving and transmitting electrical signals.

The structural and functional unit is the neuron.

Main parts of a neuron

Cell body
Dendrites
Axon

Functions

Dendrites: Receive signals.

Cell body: Contains the nucleus and maintains the cell.

Axon: Carries impulses away from the cell body.

Key concept

Dendrites → receive
Axon → transmit

Tissues Class 9 Biology Notes – CBSE & ICSE | Complete Chapter Notes — Tissues Mind Map

Most Frequently Asked Questions

What is tissue?
Why are plant and animal tissues different?
Explain meristematic tissue and its types.
Differentiate between xylem and phloem.
Differentiate between tendon and ligament.
Describe epithelial tissues.
Explain structure and function of neuron.
Differentiate between striated, smooth and cardiac muscles.
Explain stomata and their functions.
What is totipotency in plant cells?

A Note from the Author: As an educator with a background in Life Sciences and Biotechnology, I aim to simplify complex topics for students and curious minds. However, science is a rapidly evolving field. While I strive for accuracy, please use these resources as a supplement to—not a replacement for—official curriculum textbooks or professional medical consultation.