TISSUES: Types of tissues , science, class 9, CBSE

TISSUES 
A tissue is a group of cells that are similar in structure and work together to perform a particular function in the body. Example: In plants, xylem tissue helps in carrying water; in animals, muscle tissue helps in movement.

 Types of Tissues : Two types

1. Plant Tissues :Found in plants.They are of two types:

• Meristematic Tissue – Made of young, actively dividing cells. Helps in growth.

  • Apical meristem → at tips, increases length.

  • Lateral meristem → at sides, increases thickness.

  • Intercalary meristem → at nodes, helps in regrowth.

• Permanent Tissue – Made of mature cells, performs fixed functions.

  • Simple permanent tissue → parenchyma, collenchyma, sclerenchyma.

  • Complex permanent tissue → xylem (carries water), phloem (carries food).

2. Animal Tissues: Found in animals.They are of four main types:

1. Epithelial Tissue – Covers body surface, protects organs. (e.g., skin lining)

2. Connective Tissue – Joins and supports different body parts. (e.g., blood, bone, cartilage)

3. Muscular Tissue – Helps in movement by contraction and relaxation. (e.g., muscles of arm, heart)

4. Nervous Tissue – Helps in carrying messages between brain and body. (e.g., nerves, brain, spinal cord)