Tissues
Welcome to the chapter on Tissues for Class 9. In this chapter, you will learn what tissues are, the different types of tissues in plants and animals, and their functions. By the end of this chapter, you will understand how tissues help living organisms grow, move, and survive.
Introduction
A tissue is a group of similar cells that work together to do a specific job. Tissues form organs, and organs form organ systems in living beings.
Types of Tissues
- Plant Tissues: Found in plants. Examples: Meristematic tissue, Permanent tissue.
- Animal Tissues: Found in animals. Examples: Epithelial tissue, Connective tissue, Muscular tissue, Nervous tissue.
Plant Tissues
- Meristematic Tissue: Cells that divide and help plants grow. Found at the tips of roots and shoots.
- Permanent Tissue: Cells that do not divide. Types include:
- Simple Permanent Tissue: Parenchyma, Collenchyma, Sclerenchyma.
- Complex Permanent Tissue: Xylem (transports water), Phloem (transports food).
Animal Tissues
- Epithelial Tissue: Covers and protects body surfaces and organs.
- Connective Tissue: Supports and binds other tissues. Examples: Bone, blood, cartilage.
- Muscular Tissue: Helps in movement. Examples: Skeletal, smooth, cardiac muscles.
- Nervous Tissue: Carries messages between body parts and the brain.
Functions of Tissues
- Help in growth and repair.
- Transport water, food, and nutrients.
- Protect organs and body surfaces.
- Help in movement and coordination.
Fun Activity: Observe Tissues!
Look at a thin slice of onion under a microscope. You will see plant cells arranged in tissues!
Summary
- Tissues are groups of similar cells working together.
- Plants and animals have different types of tissues.
- Tissues help in growth, protection, transport, and movement.
Practice Questions
- What is a tissue?
- Name two types of plant tissues.
- Which tissue transports water in plants?
- Name two types of animal tissues.
- What is the function of nervous tissue?
Challenge Yourself
- Draw and label different types of tissues found in plants and animals.
- Explain the difference between meristematic and permanent tissue.
Did You Know?
- Blood is a connective tissue that transports oxygen and nutrients in our body!
- Plants grow taller because of meristematic tissue at the tips of roots and shoots.
Glossary
- Tissue: A group of similar cells doing a specific job.
- Meristematic Tissue: Plant tissue that divides and helps in growth.
- Permanent Tissue: Plant tissue that does not divide.
- Epithelial Tissue: Animal tissue that covers surfaces.
- Connective Tissue: Animal tissue that supports and binds.
Answers to Practice Questions
- A tissue is a group of similar cells working together to do a specific job.
- Meristematic tissue, permanent tissue.
- Xylem.
- Epithelial tissue, connective tissue (also muscular, nervous tissue).
- Nervous tissue carries messages between body parts and the brain.
Understanding tissues helps you learn how living things grow, move, and stay healthy!