🔬 Free Biology Notes & Practice Quiz
From cells to ecosystems: master life science
Biology is the science of life. From the molecular machinery inside a single cell to the vast web of ecosystems, this subject forms the backbone of NEET and Class 12. Study each topic with the notes below, then test yourself.
Start practicing Biology free →🔬 Cell Biology & Genetics
The cell is the fundamental unit of life. Understanding cell structure, division, genetics, and biomolecules gives you the foundation for all of biology.
- The Cell Class 11
Cell theory, prokaryotic vs eukaryotic cells, organelles and their functions. Foundation of all biology. - Cell Division Class 11
Mitosis and meiosis: how cells divide for growth, repair, and reproduction. - Genetics & Heredity Class 12
Mendel's laws, inheritance patterns, DNA structure, and molecular biology. Core of NEET biology. - Biomolecules & Enzymes Class 11
Carbohydrates, proteins, lipids, nucleic acids, and enzyme kinetics. Essential foundation for understanding metabolism. - Molecular Basis of Inheritance Class 12
DNA structure, replication, transcription, translation, the genetic code, and gene regulation (lac operon). The single most important chapter for NEET molecular biology.
🌿 Plant Biology
How plants grow, make food, and reproduce. Heavy NEET emphasis on physiology, hormones, and classification.
- Plant Kingdom Class 11
Classification of plants from algae to angiosperms. Understanding plant diversity is essential for NEET. - Plant Morphology & Anatomy Class 11
External structure of roots, stems, and leaves plus internal tissue organization. High marks in Class 11 and NEET. - Mineral Nutrition in Plants Class 11
Essential mineral elements, their roles and deficiency symptoms. Nitrogen fixation and soil nutrition. - Photosynthesis in Higher Plants Class 11
Light reactions, the Calvin cycle, C3/C4/CAM pathways, photorespiration, and factors affecting the rate of photosynthesis. One of the highest-yield NEET chapters. - Respiration in Plants Class 11
Glycolysis, the Krebs cycle, the electron transport chain, fermentation, and the respiratory quotient. The cellular energy-release counterpart to photosynthesis. - Plant Growth and Development Class 11
Phases of plant growth, the five classical plant hormones plus newer ones, photoperiodism, vernalization, and seed dormancy. - Transport in Plants Class 11
Water and mineral absorption, the ascent of sap, transpiration, and phloem transport via the pressure flow hypothesis. - Reproduction in Plants Class 12
Asexual and sexual reproduction, flower anatomy, pollination, fertilization, and seed development. - The Living World Class 11
Biodiversity, taxonomy, binomial nomenclature, the taxonomic hierarchy, and taxonomic aids like herbaria and botanical gardens. The foundational first chapter of NCERT Biology. - Biological Classification Class 11
Whittaker's five kingdom system covering Monera, Protista, Fungi, plus viruses, viroids, and lichens. A foundational NEET chapter on how living organisms are grouped. - Animal Kingdom Class 11
Phylum-level classification of the animal kingdom from Porifera to Chordata, based on body symmetry, coelom, and segmentation. One of the most example-heavy chapters for NEET. - Structural Organisation in Animals Class 11
The four basic animal tissue types (epithelial, connective, muscular, neural) and the cockroach as a model organism for organ-system level organisation.
❤️ Human Biology
How the human body works. The largest section for NEET with detailed anatomy, physiology, reproduction, immunity, and disease.
- Digestion and Absorption Class 11
The digestive tract, digestive enzymes, hormonal control of digestion, and liver function. High NEET weightage. - Body Fluids and Circulation Class 11
Blood, lymph, the heart, the cardiac cycle, blood pressure, and ECG. High NEET weightage. - Breathing and Exchange of Gases Class 11
The mechanics of breathing, lung volumes, gas transport in blood, the Bohr effect, and respiratory regulation. - Excretory Products and their Elimination Class 11
Nitrogenous waste, kidney structure, urine formation in the nephron, and hormonal regulation of excretion. - Chemical Coordination and Integration Class 11
The endocrine glands, hormone classification and mechanism of action, and negative feedback regulation. - Nervous System Class 11
Brain, spinal cord, neurons, reflex arcs, and sense organs. - Immune System Class 11
Innate and adaptive immunity, B cells, T cells, antibodies, vaccines, and immune disorders. Critical for NEET. - Human Reproduction Class 12
Male and female reproductive systems, gametogenesis, fertilization, implantation, pregnancy, and reproductive health. - Locomotion & Movement Class 11
Types of movement, muscle contraction, skeletal system, joints, and disorders. Important for Class 11 and NEET. - Human Health & Disease Class 12
Pathogens, infectious diseases, non-infectious diseases, drugs, cancer, and public health. High NEET importance. - Reproductive Health Class 12
Understand reproductive health, family planning, contraception methods, STIs, population control, and assisted reproductive technologies.
🌍 Ecology & Applied Biology
Ecosystems, biodiversity, evolution, environmental issues, and biotechnology.
- Ecology & Environment Class 12
Ecosystems, food chains, energy flow, nutrient cycles, biodiversity, and conservation. - Environmental Issues Class 12
Pollution, global warming, ozone depletion, deforestation, and sustainability. Important for NEET and general awareness. - Biotechnology Class 12
Recombinant DNA, GMOs, PCR, CRISPR, and biotechnology applications. Growing importance in NEET. - Evolution Class 12
Origin of life, Darwin's theory, natural selection, speciation, and evidence for evolution. - Microbes in Human Welfare Class 12
Microorganisms in food, medicine, sewage treatment, biocontrol, and biofertilizers - Strategies for Enhancement in Food Production Class 12
Learn about animal husbandry, plant breeding, tissue culture, biofortification, and single cell protein. - Organisms and Populations Class 12
How organisms interact with abiotic factors and respond to stress, plus population attributes, growth models, and interspecific interactions such as predation, competition, and mutualism.