Structural Organisation in Plants and Animals
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Introduction
The chapter “Structural Organisation in Animals and Plants” helps us understand how living organisms are built, from the cellular level to tissues, organs, and organ systems. It highlights the differences and similarities in the structural complexity of plants and animals.
I. Structural Organisation in Plants
1. Tissues in Plants
Plants are multicellular organisms with different tissues performing various functions. These tissues are classified into meristematic and permanent tissues.
A. Meristematic Tissues (Growth Tissues)
Meristematic tissues are responsible for plant growth and are found in specific regions.
B. Permanent Tissues
Once cells differentiate, they form permanent tissues that perform various functions.
1. Simple Permanent Tissues (Made of one type of cell)
- Parenchyma – Storage, photosynthesis, secretion (e.g., chlorenchyma in leaves)
- Collenchyma – Provides flexibility and mechanical support (e.g., leaf stalks)
- Sclerenchyma – Provides rigidity and strength (e.g., coconut husk)
2. Complex Permanent Tissues (Made of multiple types of cells)
- Xylem – Conducts water and minerals
- Components: Tracheids, Vessels, Xylem Parenchyma, Xylem Fibres
- Phloem – Transports food (sugar)
- Components: Sieve tubes, Companion cells, Phloem Parenchyma, Phloem Fibres
II. Structural Organisation in Animals
Animals have well-organised tissues, organs, and organ systems, which work together for survival.
1. Animal Tissues
Animal tissues are broadly classified into four types:
A. Epithelial Tissue (Covers body surfaces and organs)
- Simple Epithelium (single layer)
- Squamous (flat) – Lining of blood vessels
- Cuboidal (cube-shaped) – Glands
- Columnar (tall cells) – Intestines
- Ciliated (with cilia) – Respiratory tract
- Compound Epithelium (multiple layers) – Skin, protection against wear and tear
B. Connective Tissue (Binds, supports, and protects)
- Loose Connective Tissue – Areolar tissue (fills spaces), Adipose (stores fat)
- Dense Connective Tissue – Ligaments (bone to bone), Tendons (muscle to bone)
- Specialised Connective Tissue – Cartilage, Bone, Blood
C. Muscular Tissue (For movement)
- Skeletal Muscles – Voluntary, striated, attached to bones
- Smooth Muscles – Involuntary, non-striated, found in organs
- Cardiac Muscles – Involuntary, striated, found in the heart
D. Nervous Tissue (Sends signals)
- Neurons (nerve cells) are the main units of the nervous system
- Parts of a neuron:
- Dendrites – Receive signals
- Cell body – Processes information
- Axon – Sends signals
III. Structural Organisation of an Animal – Earthworm, Cockroach, and Frog
1. Earthworm
- Body divided into segments (Metamerism)
- Digestive System: Mouth → Pharynx → Gizzard → Intestine → Anus
- Circulatory System: Closed with blood vessels and hearts
- Nervous System: Ventral nerve cord and ganglia
- Reproduction: Hermaphrodite but cross-fertilisation occurs
2. Cockroach
- Body Segments: Head, Thorax, Abdomen
- Digestive System: Foregut → Midgut → Hindgut
- Circulatory System: Open type, haemolymph in body cavity
- Respiratory System: Tracheal system (spiracles and tubes)
- Nervous System: Ventral nerve cord
- Reproduction: Separate sexes, females lay eggs
3. Frog
- Body Parts: Head, Trunk, Limbs
- Skin: Moist and slimy for respiration
- Digestive System: Alimentary canal with liver and pancreas
- Circulatory System: Three-chambered heart, closed system
- Nervous System: Brain, spinal cord, nerves
- Reproduction: External fertilisation, tadpole larva
| Key Differences Between Plant and Animal Tissues This table presents a clear, concise comparison for students, making the topic easier to grasp! Would you like me to include diagrams or an interactive quiz for better engagement? | ||
IV. Key Differences Between Plant and Animal Tissues
V. Conclusion
- Plants and animals are built with well-organised structures.
- Plants have simple, stationary structures with growth tissues like meristems.
- Animals have complex tissues supporting movement, coordination, and response to stimuli.
- Structural adaptations help organisms survive and function efficiently in their environment.
VI. Quick Revision (Mind Map)
🟢 Plant Tissues → Meristematic (Growth) | Permanent (Simple & Complex)
🟡 Animal Tissues → Epithelial | Connective | Muscular | Nervous
🔵 Earthworm → Segmented, Closed Circulatory System
🟠 Cockroach → Exoskeleton, Open Circulatory System
🔴 Frog → Amphibian, Three-Chambered Heart