Chapter Overview:
A group of cells similar in structure dealing with a specific function is called a Tissue. This chapter
explores Plant Tissues (Meristematic, Permanent) and Animal Tissues (Epithelial, Connective, Muscular,
Nervous).
1. Plant Tissues
Plants are fixed, so they have more dead supportive tissues.
(a) Meristematic Tissue (Dividing)
Responsible for growth. Cells are active, dense cytoplasm, thin walls, prominent nuclei, no vacuoles.
- Apical: Tips of stem/root. (Height).
- Lateral (Cambium): Girth/Thickness.
- Intercalary: Base of leaves.
(b) Permanent Tissue (Non-dividing)
Formed from meristematic tissue by Differentiation.
I. Simple Permanent Tissue (One type of cells)
- Parenchyma: Living, Thin walled, Loosely packed (Intercellular spaces). Stores
food.
Modifications: Chlorenchyma (Photosynthesis), Aerenchyma (Floatation in aquatic
plants).
- Collenchyma: Living, Elongated, Thickened at corners. Provides Flexibility (Bending
without breaking).
- Sclerenchyma: Dead, Thick walls (Lignin). No intercellular spaces. Makes plant
hard/stiff. (e.g., Husk of coconut).
II. Complex Permanent Tissue (More than one type of cells)
- Xylem: Conducts water/minerals vertically. (Tracheids, Vessels, Xylem Parenchyma,
Xylem Fibres). Only Parenchyma is living.
- Phloem: Translocates food. (Sieve tubes, Companion cells, Phloem Parenchyma, Phloem
Fibres). Only Fibres are dead.
2. Animal Tissues
Animals move, so they have more living tissues.
(a) Epithelial Tissue (Protective)
Covers body surface, lines cavities. Tightly packed.
- Squamous: Flat, thin (Alveoli, Oesophagus). Diffusion.
- Stratified Squamous: Layers of squamous (Skin) to prevent wear and tear.
- Columnar: Pillar-like (Intestine). Absorption.
- Ciliated: With hair-like cilia (Respiratory tract) to push mucus.
- Cuboidal: Cube-like (Kidney tubules). Mechanical support.
(b) Connective Tissue (Binding)
Cells embedded in a matrix.
- Blood: Fluid matrix (Plasma) + RBC, WBC, Platelets. Transport.
- Bone: Hard, non-pliable matrix (Calcium/Phosphorus). Skeletal framework.
- Ligament: Connects Bone to Bone. Elastic.
- Tendon: Connects Muscle to Bone. Strong, less elastic.
- Cartilage: Flexible solid matrix (Sugar/Protein). Ear, Nose, Trachea.
- Areolar: Between skin and muscles. Packing material.
- Adipose: Stores fat below skin. Insulator.
(c) Muscular Tissue (Movement)
Contractile proteins cause movement.
| Striated (Skeletal) |
Smooth (Involuntary) |
Cardiac (Heart) |
| Voluntary. |
Involuntary. |
Involuntary. |
| Cylindrical, unbranched. |
Spindle shaped. |
Cylindrical, branched. |
| Multinucleate. |
Uninucleate. |
Uninucleate. |
| Hands, Legs. |
Stomach, Iris. |
Heart wall. |
(d) Nervous Tissue (Control)
Q1: Which tissue makes up the husk of coconut?
Ans: Sclerenchymatous tissue (Dead, Lignified).
Q2: Name the connective tissue that connects muscle to bone.
Ans: Tendon.
