BIOLOGY COMPLETE BIOLOGY MINDMAPS FOR 2 2026 - NDA Biology

Biology Mindmaps for NDA Exam

Biology for NDA is structured around concise mindmaps covering plant and animal systems, cell biology, genetics, physiology, and disease. Revision focuses on high-yield facts, classifications, and exam-specific pointers. The following sections organize the explicit content into exam-ready notes.

Plant Tissues and Their Types

Plant tissues are classified into meristematic and permanent tissues, each with distinct types and functions. Meristematic tissues are further divided into three types, while permanent tissues are of two types. Key deposition substances and cell types are frequently asked in exams.

• Meristematic Tissues: Three types; Intercalary meristem is found…

Biology Mindmaps for NDA Exam

Biology for NDA is structured around concise mindmaps covering plant and animal systems, cell biology, genetics, physiology, and disease. Revision focuses on high-yield facts, classifications, and exam-specific pointers. The following sections organize the explicit content into exam-ready notes.

Plant Tissues and Their Types

Plant tissues are classified into meristematic and permanent tissues, each with distinct types and functions. Meristematic tissues are further divided into three types, while permanent tissues are of two types. Key deposition substances and cell types are frequently asked in exams.

• Meristematic Tissues: Three types; Intercalary meristem is found at the base of leaves and grasses.
• Permanent Tissues: Two types.
• Collenchyma: Deposition of pectin.
• Sclerenchyma: Deposition of lignin.
• Xylem Cells: Four types; movement is unidirectional.
• Phloem Cells: Four types; includes living and special dead cells; movement is bidirectional.
• Differentiation: Conversion from meristematic to permanent tissue.

Respiration in Plants and Humans

Respiration involves oxygen intake and energy production from food. The process is divided into two steps, with the fate of pyruvate depending on oxygen availability. Human respiratory system pathways and lung volumes are critical for exam recall.

• Step 1: Glycolysis in cytoplasm produces pyruvate.
• Step 2: Pyruvate enters mitochondria if oxygen is present; otherwise, remains in cytoplasm.
• Anaerobic Respiration: Pyruvate forms lactic acid (causes cramps); produces less ATP.
• Fermentation: Produces ethanol, carbon dioxide, and minimal energy.
• Human Respiratory Pathway: Nasal passage → pharynx → larynx → trachea → bronchi → bronchioles (1°, 2°, 3°) → alveoli.
• Alveoli: Exchange zone; rest is conduction zone.
• Lung Lobes: Right lung has three lobes (larger); left lung has two lobes (smaller, space for heart).
• Alveolar Surface Area: 70–80 m².
• Tracheal Rings: 16–20 rings prevent collapse.

Genetic Material and Cell Division

Genetic material includes DNA and RNA, composed of nucleotides. Chromatin material forms chromosomes during cell division. Cell division occurs as mitosis or meiosis, each with distinct outcomes and significance.

• Gene: 0.1% of DNA; functional segment.
• DNA Structure: Nucleotides (sugar, phosphate, nitrogenous base).
• Nitrogenous Bases: Adenine, Thymine/Uracil, Guanine, Cytosine.
• Bonding: Hydrogen bonds; Adenine and Guanine are purines, Cytosine, Thymine, Uracil are pyrimidines.
• Chromosomes: Humans have pairs; one pair determines sex, 22 pairs are autosomes.
• Mitosis: Equational division; 2n parent produces two identical diploid daughter cells.
• Meiosis: Reductional division; occurs during gamete formation (sperm, egg); produces four genetically different haploid cells.

Lung Volumes and Capacities

Lung volumes and capacities are essential for understanding respiratory physiology. Certain volumes cannot be measured by spirometry due to the presence of residual air.

• Inspiratory Reserve Volume: 3000 ml.
• Tidal Volume: 500 ml (normal breath).
• Expiratory Reserve Volume: 1100 ml.
• Residual Volume: 1200 ml (always remains in lungs).
• Inspiratory Capacity: Maximum air inhaled forcefully.
• Vital Capacity: Maximum air inhaled and exhaled.
• Functional Residual Capacity: Air remaining after normal exhalation.
• Total Lung Capacity: Sum of all volumes; 20–30% less in females than males.
• Spirometry: Cannot measure capacities containing residual volume.

Muscle Types and Their Features

Muscle types are identified by their structure and control. Diagrams and labeling clarify their differences and functions.

• Skeletal Muscle: Only voluntary muscle.
• Cardiac Muscle: Found in heart; involuntary.
• Smooth Muscle: Found in internal organs; involuntary.
• Labeling: Key for quick revision.

Plant Hormones and Their Functions

Five plant hormones regulate growth and development, with specific roles in elongation, division, germination, stress response, and fruit ripening.

• Growth Promoters: Three hormones.
• Growth Inhibitor: One hormone.
• Dual Function Hormone: One gaseous hormone (promotes and inhibits growth).
• Auxin: Promotes growth via cell elongation.
• Cytokinin: Promotes growth via cell division.
• Gibberellin: Promotes seed germination.
• Abscisic Acid: Stress hormone; inhibits seed germination in unfavorable conditions.
• Ethylene: Promotes fruit ripening.

Endosymbiotic Theory and Cell Organelles

Certain organelles possess their own DNA and ribosomes, supporting the endosymbiotic theory. These organelles were once prokaryotic and now function within eukaryotic cells.

• Mitochondria and Chloroplasts: Have their own DNA and ribosomes.
• Theory: These organelles entered eukaryotic cells and became semi-autonomous.
• Names: "Cell within a cell" and "semi-autonomous organelles."

Kingdoms in Biology

Plant and animal kingdoms are classified based on evolutionary advancement and structural features. Five-kingdom classification is based on cell type, structure, and nutrition.

• Plant Kingdom: Thallophyta (most primitive), flowering plants (most advanced).
• Questions: Amphibians of plant kingdom, seed covering, first vascular structures, double fertilization, cryptogams.
• Five Kingdoms (R.H. Whittaker): Monera, Protista, Fungi, Plantae, Animalia.
• Monera: Prokaryotic, unicellular.
• Protista: Eukaryotic, unicellular.
• Animalia: Eukaryotic, multicellular, no cell wall.
• Fungi: Eukaryotic, multicellular, cell wall, heterotrophic.
• Plantae: Eukaryotic, multicellular, cell wall, autotrophic.
• Six Kingdoms: Monera split into two by Carlus.

Nervous System and Epithelial Tissue

The nervous system is divided into central and peripheral components, with further subdivisions. Epithelial tissue forms protective coverings and varies by location and structure.

• Nervous System: Central and peripheral; peripheral includes autonomic (involuntary) and somatic.
• Autonomic System: Activated during fear or calm states.
• Cranial and Spinal Nerves: Important for recall.
• Epithelial Tissue: First line of protection; types depend on location.
• Simple Epithelium: Single layer; various shapes.
• Stratified Epithelium: Multiple layers; various shapes.
• Special Types: Three mentioned.
• Exam Questions: Type of epithelium in pharynx, intestine, stomach, anus, epiglottis, male urethra, urinary bladder, fallopian tube.

Animal Kingdom and Digestive System

Animal kingdom is divided by cellular and tissue levels, symmetry, and coelom types. Digestive system is mapped from mouth to intestines, with key enzymes and absorption points.

• Cellular Level: Porifera (most primitive).
• Radial Symmetry: Coelenterata.
• Bilateral Symmetry: Advanced phyla; acoelomate, pseudocoelomate, coelomate.
• Exam Questions: Phylum with pseudocoelomate.
• Digestive Pathway: Mouth → food pipe (bolus) → stomach (mechanical and chemical digestion) → small intestine (chyme) → pancreas and liver secretions → absorption.
• Stomach Secretions: HCl, mucus, pepsinogen, lipase, intrinsic factor.
• Small Intestine: Three parts; digestion completes, maximum absorption.
• Large Intestine: Three parts.

Nutrients, Vitamins, and Minerals

Nutrients are classified as macro and micro, with specific caloric values and deficiency diseases. Vitamins are divided into fat-soluble and water-soluble types.

• Macronutrients: Carbohydrates, fats, proteins; caloric values stated.
• Micronutrients: Vitamins, minerals.
• Fat-Soluble Vitamins: Names and functions listed.
• Water-Soluble Vitamins: Names, functions, deficiency diseases.
• Exam Focus: Vitamin-related questions are frequent.

Endocrine Glands and Hormonal Control

Endocrine glands release hormones affecting various body functions. Deficiency or excess leads to specific diseases, with arrows indicating direction of change.

• Glands: Pituitary, pineal, thyroid, parathyroid, thymus, pancreas, adrenal, gonads.
• Diseases: Listed for deficiency and excess.
• Hypothyroidism/Hyperthyroidism: Direction indicated by arrows.

Sexual Reproduction in Flowering Plants

Sexual reproduction involves distinct male and female structures, gamete formation, and double fertilization. The process is detailed for exam recall.

• Male Structure: Anther contains pollen bags; each pollen grain has two male gametes.
• Female Structure: Stigma, style, ovary; ovary contains cell undergoing meiosis and mitosis to form embryo sac.
• Fusion: One male gamete fuses with egg, another with secondary nucleus; results in double fertilization.

Diseases and Lines of Defense

Diseases are classified by causative agents, with color coding aiding memory. The body’s defense lines include specific enzymes and immune cells.

• Disease Types: Bacterial (blue), viral, fungal.
• Examples: Typhoid (bacterial), chickenpox (viral), rabies (viral), scabies (fungal).
• First Line of Defense: Lysozyme (antibacterial enzyme).
• Second Line: Fever, inflammation.
• Third Line: B cells, T cells (lymphocytes); natural and artificial immunity, vaccination.

Circulatory System and Cell Organelles

Circulatory system features double circulation, heart chambers, valves, and electrical conduction. Cell organelles are mapped with their functions.

• Double Circulation: Blood passes through heart twice; oxygenated and deoxygenated flows.
• Heart Chambers: Four in mammals and birds.
• Valves: Four types; locations specified.
• Electrical Conduction: SA node, AV node, bundle of His, Purkinje fibers.
• Prokaryotic Cell: One chromosome, unicellular, no defined nucleus (nucleoid), ribosome type specified.
• Plastids: Chloroplast (green pigment), chromoplast (other pigments), leucoplast (colorless, storage).

Blood Cells and Cell Discovery

Blood cells include RBCs, WBCs, and platelets, with lifespan and count per mm³ stated. Cell discovery and theory are attributed to specific scientists.

• RBCs, WBCs, Platelets: Lifespan and count per mm³ listed.
• WBC Types: Functions specified.
• Cell Discovery: Scientist names and years mentioned.
• Cell Theory: Two scientists; modification and points stated.

Plasma Membrane Composition

Plasma membrane is present in all living organisms and is composed of specific substances. The presence in viruses is questioned for exam practice.

• Composition: Explicit substances listed.
• Presence: Found in all living organisms; question posed about viruses.