CBSE Class 12 Biology Syllabus 2026-27: Detailed Unit-wise Breakdown

CBSE Class 12 Biology Syllabus 2026-27 is a comprehensive roadmap designed for students preparing for board exams and competitive medical entrance tests. It covers five core units: Reproduction, Genetics and Evolution, Biology and Human Welfare, Biotechnology and Its Applications, and Ecology and Environment, combining theory and practical components for a total of 100 marks. The syllabus emphasizes both conceptual understanding and practical skills, including experiments, slide preparation, spotting, viva, and project work. 

Students are encouraged to refer to the official biology class 12 syllabus 2026-27 PDF to ensure complete coverage of all chapters, marking schemes, and important topics for effective exam preparation.

CBSE Class 12 Biology Syllabus 2026-27 Overview

The Biology (Code No. 044) examination for Class 12 consists of a theory paper of 70 marks and a practical assessment of 30 marks.

CBSE Class 12 Biology Syllabus 2026-27 PDF Download

Students can conveniently access the complete CBSE Class 12 Biology Syllabus 2026-27 in PDF format for easy reference and systematic preparation. The PDF contains all units, chapters, mark distribution, and practical details, making it an essential resource for board exam revision and practice.

CBSE Class 12 Biology Syllabus 2026-27 PDF Download

Class 12 Biology Syllabus 2026-27 Unit-wise Detailed Breakdown

The Class 12 Biology Syllabus 2026-27 is carefully designed to cover essential concepts of life sciences, helping students excel in CBSE board exams and competitive medical entrance tests. The syllabus includes five main units, combining theory (70 marks) and practicals (30 marks). Below is a detailed unit-wise breakdown:

Unit I: Reproduction (14 Marks)

This unit explains reproduction in plants and animals, along with human reproductive health.

Chapters and Topics:

1. Reproduction in Organisms

• Life span of organisms.

• Modes of reproduction: asexual (binary fission, budding, spore formation) and sexual.

• Significance of reproduction in species continuity.

2. Sexual Reproduction in Flowering Plants

• Flower structure and types.

• Development of male and female gametophytes.

• Pollination: self and cross-pollination.

• Fertilization, double fertilization, seed and fruit formation.

3. Human Reproduction

• Male reproductive system: testis, sperm production, hormonal regulation.

• Female reproductive system: ovary, ovulation, hormonal control.

• Gametogenesis: spermatogenesis and oogenesis.

• Menstrual cycle, fertilization, implantation, pregnancy, parturition.

4. Reproductive Health

• Importance of reproductive health.

• Contraception methods.

• Sexually transmitted diseases (STDs).

• Assisted Reproductive Technologies (ART) like IVF, surrogacy.

Unit II: Genetics and Evolution (18 Marks)

This is the highest-weightage unit in the syllabus, covering inheritance, molecular genetics, and evolutionary biology.

Chapters and Topics:

1. Principles of Inheritance and Variation

• Mendel’s laws of inheritance.

• Deviations from Mendelism: incomplete dominance, co-dominance.

• Linkage, recombination, and chromosomal theory of inheritance.

• Sex determination in humans, sex-linked traits.

• Common genetic disorders (Down syndrome, Thalassemia, Sickle Cell Anemia).

2. Molecular Basis of Inheritance

• Structure of DNA and RNA.

• DNA replication, transcription, translation.

• Genetic code, regulation of gene expression.

• Human Genome Project and DNA fingerprinting.

3. Evolution

• Origin of life theories.

• Darwinian theory of natural selection.

• Lamarck’s theory.

• Modern synthetic theory of evolution.

• Hardy-Weinberg principle, adaptive radiation.

• Evidences of evolution: fossil, anatomical, molecular, embryological.

Unit III: Biology and Human Welfare (14 Marks)

This unit explains how biology is applied to improve human life and health.

Chapters and Topics:

1. Human Health and Disease

• Pathogens causing diseases: Malaria, Typhoid, Pneumonia, Common Cold.

• Immunity: innate and acquired.

• Vaccines and their importance.

• Cancer, drug abuse, alcohol effects.

2. Strategies for Enhancement in Food Production

• Plant breeding and hybrid varieties.

• Tissue culture techniques.

• Animal husbandry and dairy management.

• Apiculture and fisheries.

3. Microbes in Human Welfare

• Role in household food production (bread, curd, cheese).

• Industrial applications: antibiotics, biofertilizers, biogas, sewage treatment.

• Biocontrol agents for pest management.

Unit IV: Biotechnology and Its Applications (10 Marks)

This unit introduces modern biotechnology and its applications in agriculture, medicine, and industry.

Chapters and Topics:

1. Biotechnology – Principles and Processes

• Genetic engineering concepts.

• Tools: restriction enzymes, plasmids, vectors.

• Recombinant DNA technology, cloning, and gene manipulation.

2. Biotechnology and Its Applications

• Applications in agriculture: Bt cotton, pest-resistant crops.

• Applications in medicine: production of human insulin, vaccines.

• Transgenic animals, gene therapy.

• Ethical issues, biopiracy, biosafety measures.

Unit V: Ecology and Environment (14 Marks)

This unit deals with ecosystems, biodiversity, environmental issues, and conservation strategies.

Chapters and Topics:

1. Organisms and Populations

• Population interactions: mutualism, competition, predation.

• Population growth models: exponential, logistic.

• Adaptations of organisms to environments.

2. Ecosystem

• Structure and function of ecosystems.

• Productivity, decomposition, energy flow.

• Food chains, food webs, ecological pyramids, nutrient cycles.

3. Biodiversity and Conservation

• Types of biodiversity: genetic, species, ecosystem.

• Biodiversity hotspots, threats to biodiversity.

• Conservation methods: in-situ and ex-situ strategies.

4. Environmental Issues

• Air, water, and soil pollution.

• Deforestation, global warming, ozone depletion.

• Waste management and sustainable practices.

Practical Examination (30 Marks)

The practical component of the biology class 12 syllabus 2026-27 PDF includes:

1. Major Experiment: 5 Marks

2. Minor Experiment: 4 Marks

3. Slide Preparation: 5 Marks

4. Spotting: 7 Marks

5. Practical Record, Viva, and Project: 9 Marks

Preparation Tips for Class 12 Biology

• Diagram Practice: Biology is a visual subject. Ensure you can draw and label diagrams like the DNA double helix, human reproductive systems, and the structure of a flower.

• NCERT Primacy: The board exam strictly follows NCERT textbooks. Read every line of the chapters mentioned in the biology class 12 syllabus.

• Solve Sample Papers: Regular practice of previous years' questions helps in understanding the weightage of specific topics within a unit.

For structured guidance and exam-oriented learning resources, students can explore specialized foundation and board-prep courses at Physics Wallah. Our programs are designed to simplify complex biological processes through expert-led sessions.