Structural Organisation In Animals And Plants Revision Notes for Biology NEET

The chapter "Structural Organisation in Animals and Plants" explores the internal and external structures of both plants and animals. This is crucial for understanding how specialized functions develop in multicellular organisms through the differentiation and modification of their parts. For NEET Biology, revising key points from morphology, anatomy, tissues, and organ systems as described in this chapter will help consolidate concepts and improve problem-solving skills.

Morphology and Modifications Morphology deals with the external features and form of plants. In flowering plants, root, stem, and leaf are the three main organs. Roots may show modifications like storage (as in carrot), support (as in banyan), respiration (as in mangrove), and reproduction (as in sweet potato). Stems can be modified for storage (potato tuber), vegetative propagation (ginger rhizome), protection (thorn in bougainvillea), and climbing (tendril in grapevine). Leaves may also have special roles such as spines for protection (cactus), tendrils for climbing (peas), or storage of food and water (onion, aloe).

Tissues in Plants Tissues are groups of cells having a common origin and performing specific functions. Plant tissues are mainly divided into meristematic (actively dividing) and permanent tissues (differentiated). Meristematic tissues are located at root and shoot tips (apical meristem), while lateral meristem (cambium) causes secondary growth. Permanent tissues include simple (parenchyma, collenchyma, sclerenchyma) and complex tissues (xylem, phloem). Parenchyma helps in storage and photosynthesis, collenchyma provides flexibility, and sclerenchyma offers mechanical support.

Anatomy and Functions of Plant Parts Plants have roots, stems, and leaves with specialized anatomy.

• Root: Functions in anchorage and absorption; consists of epidermis, cortex, endodermis, pericycle, and vascular bundles (xylem and phloem arranged alternately).
• Stem: Supports leaves and reproductive organs; features nodes, internodes; contains vascular bundles (in dicots - ring arrangement, monocots - scattered).
• Leaf: Main site for photosynthesis; features cuticle, epidermis, mesophyll (palisade and spongy parenchyma), and vascular bundles forming veins.

Inflorescence Types Inflorescence refers to the arrangement of flowers on the plant. The two main types are:

• Cymose: Main axis has limited growth; central flowers open first (e.g., jasmine, hibiscus).
• Racemose: Main axis grows continuously; youngest flowers at the apex (e.g., mustard, lupin).

Structure of Flower, Fruit, and Seed A typical flower has four main whorls: calyx (sepals), corolla (petals), androecium (stamens), and gynoecium (carpels). Post-fertilization, the ovary becomes the fruit, while the ovule gives rise to the seed. Fruits can be simple (mango), aggregate (strawberry), or multiple (pineapple). Seeds have seed coats, cotyledons, and embryonic axis; dicots have two cotyledons, monocots have one.

Important Plant Families Key plant families you should remember include:

• Malvaceae: (e.g., cotton, hibiscus) - Flowers actinomorphic, stamens monadelphous.
• Cruciferae: (Brassicaceae, e.g., mustard) - Flowers cruciform, tetradynamous stamens.
• Leguminosae: (e.g., peas, beans) - Zygomorphic flowers, fruits are legumes.
• Compositae: (Asteraceae, e.g., sunflower) - Compound inflorescence called capitulum, florets of two types.
• Gramineae: (Poaceae, e.g., wheat, rice) - Stem hollow with nodes, leaves sheathing, flowers reduced in spikelets.

Animal Tissues Animal tissues are classified into four basic types:

• Epithelial tissue: Forms outer and inner lining; includes squamous epithelium (lining of blood vessels), cuboidal (kidney tubules), and columnar (gut lining).
• Connective tissue: Supports and binds other tissues; includes bone, cartilage, blood, tendons, and ligaments.
• Muscular tissue: Helps in movement; types are skeletal (voluntary), smooth (involuntary), and cardiac (only in heart).
• Nervous tissue: Specialized for impulse conduction; made up of neurons and neuroglia.

Morphology, Anatomy and Functions in Frog (Brief Account) Frog is a representative animal studied for understanding systems in vertebrates. Its body is streamlined with head and trunk, lacking a neck or tail in adults. Major organ systems found in frog are as follows:

• Digestive System: Consists of mouth, buccal cavity, pharynx, oesophagus, stomach, intestine, and cloaca. Liver and pancreas as digestive glands. Main function is the digestion and absorption of food.
• Circulatory System: Has a three-chambered heart (2 atria, 1 ventricle), blood vessels, and blood. Transports oxygen, nutrients, and waste products.
• Respiratory System: Respiration by skin (cutaneous), buccal cavity (buccopharyngeal), and lungs (pulmonary) depending on condition (land or water).
• Nervous System: Comprises brain, spinal cord, and peripheral nerves. Helps in coordination and response to stimuli.
• Reproductive System: Separate sexes. Male has testes, female has ovaries. Fertilization is external, development is indirect (via tadpole stage).

Quick Comparison Table: Plant vs Animal Tissues

Feature	Plant Tissues	Animal Tissues
Types	Meristematic, Permanent	Epithelial, Connective, Muscular, Nervous
Growth	Continues throughout life (meristems)	Limited, mostly in early stages
Cell Wall	Present	Absent
Regeneration	High	Variable

Key Points to Remember

• Morphological and anatomical adaptations help plants and animals survive in diverse environments.
• Knowledge of tissues, organ systems and their functions forms the foundation for understanding physiology and development in higher organisms.
• Practice drawing and labeling diagrams for tissues, plant parts, and systems for NEET.

NEET Biology Revision Notes – Structural Organisation in Animals and Plants

These NEET revision notes for Structural Organisation in Animals and Plants focus on morphology, anatomy, and tissue-level details in both plants and animals. Important plant families and animal tissues are presented in simple language. Grasping these key points will strengthen your subject fundamentals for competitive exams.

Clear explanations and useful tables make your last-minute revision more efficient. Reviewing concise concepts of roots, stems, inflorescence, and animal organ systems can give you an edge in NEET Biology. These notes support strategic preparation and help you recall faster during the exam.