Class 9 science notes in english Chapter 6 tissue

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9th Class Science Notes in English chapter 6 Tissue.


CBSE Revision Notes for CBSE Class 09 Science Tissues, Tissues: Structure and functions of animal and plant tissues (only four types of tissues in animals; Meristematic and Permanent tissues in plants) for class 09 Science. It includes all main concepts of the chapter in CBSE class 09 Science.

Class 9th Science chapter 6 Tissue Notes in English.

📚 Chapter - 6 📚

🔹 TISSUE 🔹

Introduction to Tissues :-

✳️Tissues :-
🔹 Group of cells having a common origin and similar function are termed as tissues.

👉 Tissues are mainly classified into two types:-
      🔹 (A) Plant Tissues 
      🔹 (B) Animal Tissues

✳️ (A) Plant Tissues
🔹Plant tissues are of various types and they are made up of similar types of cells. They are different from animal tissues since there are several differences between the animal and plant cell.


9th Class Science Notes in English chapter 6 Tissue

    

👉 On the basis of the dividing capacity, Plant Tissues are of two types:-

             🔹 (1) Meristematic Tissues

             🔹 (2) Permanent Tissues


✳️ (1) Meristematic Tissues:- Meristematic tissues are responsible for growth in plants. 

    👉 Meristematic Tissues are of three types:-

9th Class Science Notes in English chapter 6 Tissue
  🔹(i) Apical Meristem:- It is present at the growing tip of the stem and roots and increases the length. 

  🔹(ii) Intercalary Meristem:- It is present at internodes or base of the leaves and increases the length between the nodes. 

  🔹(iii) Lateral Meristem (Cambium):- It is present beneath the bark. It is responsible for growth in girth of trunk.


✳️ (2) Permanent Tissue :- The tissues that are completely grown and have lost the ability of division are known as permanent tissues. The meristematic tissues divide and differentiate to form the permanent tissues.


👉 Permanent Tissues are of two types:-

🔹(i) Simple Tissues  

🔹(ii) Complex Tissues


✳️ (i) Simple Permanent Tissue:- Consist of only one type of cells.

  👉 Types of Simple Permanent Tissues:

    🔹Parenchyma:- Composed of unspecialised living cells with relatively thin cell walls, intercellular space, present in soft parts of the plant. Their main function is storage.

9th Class Science Notes in English chapter 6 Tissue


    🔹Collenchyma:- Composed of living and elongated cells with cell walls irregularly thickened at the comers. No intercellular space. It provides mechanical support and elasticity to plant. It helps in bending of leaves and stems.

9th Class Science Notes in English chapter 6 Tissue


     🔹Sclerenchyma:- Composed of long, narrow, and thick-walled cells. This tissue is made up of dead cells and there are no intercellular spaces. Sclerenchyma cells are dead, present in seeds, nuts, the husk of a coconut, fibres of jute etc.

9th Class Science Notes in English chapter 6 Tissue


✳️ (ii) Complex Permanent Tissue:- Made up of more than one type of cells (Conducting tissues.)

   👉 Types of Complex Permanent Tissues:

     🔹Xylem:- Conducts water and minerals from the roots to the different parts of the plant.
9th Class Science Notes in English chapter 6 Tissue


          ▶ Composed of four different types of cells :-
              🔹 Tracheids 
              🔹 Vessels
              🔹 Xylem Parenchyma 
              🔹 Xylem Fibres

     🔹Phloem:- Conducts food material from the leaves to the different parts of the plant.

9th Class Science Notes in English chapter 6 Tissue


          ▶ Composed of four different types of Cells :-
              🔹 Sieve Tubes
              🔹 Companion Cells
              🔹 Phloem Parenchyma
              🔹 Phloem Fibres

 ✳️ (iii) Protective Tissue:- It is made of a single layer of cells.
 
   👉 There are two types of protective Tissues:-

      🔹Epidermis Simple Tissues:- Epidermis tissue covers the entire body of plant. They protect plant from injury, germs and water loss.

9th Class Science Notes in English chapter 6 Tissue


      🔹Cork Simple Tissues:- These types of tissue consist  dead cells with no intercellular spaces. They form the outer layer of old tree trunks.

9th Class Science Notes in English chapter 6 Tissue


✳️ (B) Animal Tissues

🔹 Animal tissues are made up of animal cells. These tissues are usually not rigid since the cells do not have cell walls.

9th Class Science Notes in English chapter 6 Tissue


   👉 Animal tissues are classified into four types based on the functions they perform:-

       🔹 Epithelial 
      🔹 Connective
      🔹 Muscular 

      🔹 Nervous

 ✳️ Epithelial Tissues:- Form the covering of the external surfaces, internal cavities and organs of the animal body. 

    👉 Various types of Epithelial Tissues are:-

    🔹Simple squamous epithelium:- Single layer of flat cells.

    🔹Location in the human body:- Lining of the mouth, oesophagus, lung, alveoli, etc.

    🔹Cuboidal epithelium: Consists of cube like cells.

    🔹Location in the human body:- Lining of the kidney tubules and ducts of the salivary glands. It’s function is secretion and absorption.

    🔹Columnar epithelium:- Consists of elongated or column-like cells.

    🔹Location in the human body:- Inner lining of the intestine and gut. Its function is of secretion and absorption.


✳️ Connective Tissues:- Specialised to connect various body organs. 

👉 Various types of connective tissues are:

    🔹Areolar tissue:- Found in the skin and muscles, around the blood vessels, nerves, etc.

    🔹Adipose tissue:- Acts as the storage site of fats; found between the internal organs and below the skin; acts as an insulator for the body.

    🔹Dense regular connective tissue:- Main components are tendons and ligaments; tendons connect muscles to bones, while ligaments connect two bones together.

    🔹Skeletal tissue:- Main components of skeletal tissues are cartilage and bone.

    🔹Fluid tissue:- Blood is the vascular tissue present in animals.


✳️ Muscular Tissues:- Main function of muscular tissues is to provide movement to the body. Muscular tissues are of three types:

    🔹Striated muscles or skeletal muscles or voluntary muscles:- Cells are cylindrical, unbranched and multinucleate.


9th Class Science Notes in English chapter 6 Tissue



    🔹Smooth muscles or involuntary muscles:- Cells are long, spindle-shaped and possess a single nucleus.

                         9th Class Science Notes in English chapter 6 Tissue

    🔹Cardiac muscles or involuntary muscles:- Cells are cylindrical, branched and uninucleate.

  9th Class Science Notes in English chapter 6 Tissue


✳️ Nervous Tissues:- Present in the brain, spinal cord and nerves.

9th Class Science Notes in English chapter 6 Tissue

    🔹Neurons:- These are the cells that form the entire nervous system. The cell consists of a cell body, axon and axon terminals.