Chapter-Tissues in Action Science Exploration class 9 in english Medium CBSE Notes

Chapter 3. Tissues in Action

This section explains the complex permanent tissues of plants and the different types of animal tissues. It also describes how these tissues help in transport, protection, support, movement and coordination in living organisms.

15. Complex Permanent Tissue

Complex permanent tissues are made up of more than one type of cells. All these cells work together to perform a common function, mainly the transportation of water, minerals and food throughout the plant.

Definition

Complex permanent tissue is a tissue composed of different kinds of cells working together to perform a specific function.

Types of Complex Permanent Tissue

• Xylem – Transports water and minerals from the roots to different parts of the plant.
• Phloem – Transports prepared food from leaves to all parts of the plant.

16. Xylem

Xylem is the conducting tissue responsible for carrying water and dissolved minerals from the roots to the stem, leaves and other plant parts.

Definition

Xylem is a complex permanent tissue that transports water and minerals upward in the plant.

Components of Xylem

• Tracheids – Conduct water and provide support.
• Vessels – Main conducting elements in flowering plants.
• Xylem Fibres – Provide mechanical strength.
• Xylem Parenchyma – Stores food and helps in lateral transport.

Functions

• Transport of Water – Carries water from roots to leaves.
• Transport of Minerals – Supplies essential minerals throughout the plant.
• Mechanical Support – Makes the plant strong and upright.

17. Phloem

Phloem transports the food prepared in the leaves to all growing and storage regions of the plant.

Definition

Phloem is a complex permanent tissue responsible for transporting food in plants.

Components of Phloem

• Sieve Tubes – Main food-conducting cells.
• Companion Cells – Help sieve tubes in food transport.
• Phloem Parenchyma – Stores food.
• Phloem Fibres – Provide mechanical support.

Functions

• Food Transport – Carries prepared food to different plant parts.
• Storage – Stores food materials.
• Support – Strengthens plant tissues.

18. Difference Between Xylem and Phloem

Xylem	Phloem
Transports water and minerals.	Transports prepared food.
Mainly upward movement.	Transport may occur in both directions.
Mostly dead cells.	Mostly living cells.
Provides mechanical support.	Mainly transports food.

19. Animal Tissues

Animal tissues are specialised groups of cells that perform different functions such as protection, support, movement and coordination. Unlike plants, animals require tissues that help them move and respond quickly to their surroundings.

Classification of Animal Tissues

• Epithelial Tissue
• Connective Tissue
• Muscular Tissue
• Nervous Tissue

20. Epithelial Tissue

Epithelial tissue forms the protective covering of the body and lines internal organs and cavities. It protects the body from injury, infection and dehydration.

Definition

Epithelial tissue is a protective tissue that covers body surfaces and lines internal organs.

Functions

• Protection – Protects internal organs.
• Absorption – Absorbs nutrients in the intestine.
• Secretion – Forms glands that produce useful substances.
• Exchange of Materials – Helps in the exchange of gases in the lungs.

21. Connective Tissue

Connective tissue connects, supports and protects different parts of the body. It is the most abundant tissue in animals.

Definition

Connective tissue is a tissue that binds, supports and connects different organs and tissues.

Types of Connective Tissue

• Blood – Transports oxygen, nutrients and waste materials.
• Bone – Provides support and protects internal organs.
• Cartilage – Provides flexibility at joints.
• Tendon – Connects muscles to bones.
• Ligament – Connects one bone to another bone.

22. Muscular Tissue

Muscular tissue is responsible for all types of body movements. Muscle cells contract and relax to produce movement.

Types of Muscular Tissue

• Skeletal Muscle – Voluntary muscles attached to bones.
• Smooth Muscle – Involuntary muscles found in internal organs.
• Cardiac Muscle – Special involuntary muscle found only in the heart.

Muscle Type	Control	Location
Skeletal Muscle	Voluntary	Attached to bones
Smooth Muscle	Involuntary	Walls of internal organs
Cardiac Muscle	Involuntary	Heart

23. Nervous Tissue

Nervous tissue helps the body receive, process and respond to different stimuli. It controls coordination between different organs.

Definition

Nervous tissue is a specialised tissue responsible for transmitting nerve impulses.

Neuron

A neuron is the structural and functional unit of the nervous system.

Functions

• Receives Stimuli – Detects changes in the surroundings.
• Transmits Nerve Impulses – Carries messages between different body parts.
• Controls Coordination – Helps different organs work together.

24. ATP Education Quick Comparison

Plant Tissue	Main Function
Meristematic	Growth
Parenchyma	Storage
Collenchyma	Flexibility
Sclerenchyma	Mechanical Strength
Xylem	Water Transport
Phloem	Food Transport

ATP Education Tip

For CBSE examinations, remember these high-scoring concepts: Xylem transports water, Phloem transports food, Tendon connects muscle to bone, Ligament connects bone to bone, Blood is a connective tissue, and Neuron is the structural and functional unit of the nervous system. These topics are frequently asked in objective, competency-based and case-study questions.

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