Science Class 11 - Structural Organisation-In-Plants-And-Animals Notes

Structural Organisation in Plants and Animals

Welcome to the chapter on Structural Organisation in Plants and Animals for Class 11. In this chapter, you will learn about how plants and animals are built, from cells to tissues, organs, and organ systems. By the end of this chapter, you will understand the basic structure and function of different tissues and organs in both plants and animals.

Introduction

All living organisms are made up of cells. In multicellular organisms, cells are organised into tissues, tissues into organs, and organs into organ systems. This organisation helps living beings perform various functions efficiently.

Structural Organisation in Plants

• Cell: The basic unit of life in plants.
• Tissue: A group of similar cells performing a specific function.
• Organ: Different tissues combine to form organs like roots, stems, and leaves.

Plant Tissues

• Meristematic Tissue: Responsible for growth. Found at the tips of roots and shoots.
• Permanent Tissue: Formed from meristematic tissue. Includes simple tissues (parenchyma, collenchyma, sclerenchyma) and complex tissues (xylem and phloem).

Plant Organs

• Root: Anchors the plant and absorbs water and minerals.
• Stem: Supports the plant and transports nutrients.
• Leaf: Main site of photosynthesis.
• Flower: Reproductive organ of the plant.

Structural Organisation in Animals

• Cell: The basic unit of life in animals.
• Tissue: A group of similar cells performing a specific function.
• Organ: Different tissues combine to form organs like heart, lungs, and stomach.
• Organ System: Organs work together to perform major functions (e.g., digestive system, respiratory system).

Animal Tissues

• Epithelial Tissue: Covers body surfaces and lines organs.
• Connective Tissue: Supports and binds other tissues (e.g., bone, blood, cartilage).
• Muscular Tissue: Helps in movement.
• Nervous Tissue: Transmits signals and coordinates body functions.

Animal Organs and Systems

• Digestive System: Breaks down food and absorbs nutrients.
• Respiratory System: Exchanges gases (oxygen and carbon dioxide).
• Circular System: Transports blood and nutrients.
• Nervous System: Controls body activities and responses.

Practice Questions

1. What is the difference between meristematic and permanent tissue in plants?
2. Name two types of animal tissues and their functions.
3. What is the main function of the root in a plant?
4. List any two organ systems in animals and their functions.
5. Why is structural organisation important in multicellular organisms?

Challenge Yourself

• Draw and label a diagram of plant tissues and animal tissues.
• Explain how different tissues work together to form an organ in animals.

Did You Know?

• The human body has over 200 different types of cells!
• Plants can have tissues that store water, helping them survive in deserts.

Glossary

• Cell: The smallest unit of life.
• Tissue: A group of similar cells working together.
• Organ: A part of the body made of different tissues that does a special job.
• Organ System: A group of organs working together for a major function.

Answers to Practice Questions

1. Meristematic tissue helps in growth; permanent tissue performs specific functions after growth.
2. Epithelial tissue (covers surfaces), muscular tissue (helps in movement).
3. To anchor the plant and absorb water and minerals from the soil.
4. Digestive system (breaks down food), respiratory system (exchanges gases).
5. It allows different parts to do different jobs, making the organism efficient and complex.

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Understanding structural organisation helps us learn how living things grow, survive, and function!