Biology is one of the most important subjects in Class 12 for students aspiring to pursue careers in medicine, biotechnology, genetics, and life sciences. The Class 12th Biology syllabus 2025-26 prescribed by CBSE is carefully designed to provide a strong foundation in advanced concepts like Reproduction, Genetics, Evolution, Biotechnology, Human Welfare, and Ecology.
Along with theory, practical work plays a major role in developing experimental and analytical skills. This blog gives you the complete syllabus, unit-wise weightage, exam pattern, prescribed books, preparation tips, project topics, and a downloadable PDF to help you prepare effectively for the board exams.
Class 12 Biology Syllabus 2025-26: Overview
Below is the overview of class 12th biology syllabus:
| Unit No. | Unit Name | Marks |
| I | Reproduction | 14 |
| II | Genetics and Evolution | 18 |
| III | Biology and Human Welfare | 14 |
| IV | Biotechnology and Its Applications | 10 |
| V | Ecology and Environment | 14 |
| Total (Theory) | 70 | |
| Practical | Experiments, Spotting, Slide Preparation, Viva, Record, Project | 30 |
| Grand Total | 100 |
Download Class 12 Biology Syllabus PDF
To make your preparation easier, we’ve provided the official CBSE Class 12 Biology Syllabus 2025-26 PDF.
Class 12th Biology Syllabus 2025-26
Let’s discuss in detail the syllabus for class 12 biology:
Unit I: Reproduction (14 Marks)
This unit explains the process of reproduction in plants and animals, along with human reproductive health.
| Chapter | Details Covered |
| Reproduction in Organisms | Life span, modes of reproduction – asexual and sexual, significance of reproduction. |
| Sexual Reproduction in Flowering Plants | Flower structure, pollination, fertilization, double fertilization, seed and fruit formation. |
| Human Reproduction | Male and female reproductive systems, gametogenesis, menstrual cycle, fertilization, implantation, pregnancy, parturition. |
| Reproductive Health | Need for reproductive health, contraception, sexually transmitted diseases, assisted reproductive technologies (ART). |
Unit II: Genetics and Evolution (18 Marks)
This unit in syllabus for class 12 biology covers the molecular and chromosomal basis of inheritance, genetic disorders, and evolutionary biology.
| Chapter | Details Covered |
| Principles of Inheritance and Variation | Mendel’s laws, deviations, linkage and recombination, chromosomal theory, sex determination, genetic disorders. |
| Molecular Basis of Inheritance | DNA structure, replication, transcription, translation, genetic code, regulation of gene expression, human genome project, DNA fingerprinting. |
| Evolution | Origin of life, theories of evolution (Darwin, Lamarck), Hardy-Weinberg principle, adaptive radiation, evidences of evolution. |
Unit III: Biology and Human Welfare (14 Marks)
This unit in biology syllabus for class 12 focuses on the role of biology in improving human life and combating diseases.
| Chapter | Details Covered |
| Human Health and Disease | Pathogens causing diseases (malaria, typhoid, pneumonia, common cold), immunity, vaccines, cancer, drug and alcohol abuse. |
| Strategies for Enhancement in Food Production | Plant breeding, tissue culture, animal husbandry, dairy management, apiculture, fisheries. |
| Microbes in Human Welfare | Role of microbes in industries, antibiotics, biofertilizers, sewage treatment, energy production, biocontrol agents. |
Unit IV: Biotechnology and Its Applications (10 Marks)
This unit in biology syllabus for class 12 explains the principles, processes, and applications of biotechnology.
| Chapter | Details Covered |
| Biotechnology – Principles and Processes | Genetic engineering, tools (restriction enzymes, vectors), recombinant DNA technology, cloning. |
| Biotechnology and Its Applications | Applications in agriculture (Bt cotton), medicine (insulin, vaccines), transgenic animals, ethical issues, biopiracy, biosafety. |
Unit V: Ecology and Environment (14 Marks)
This unit explains ecosystems, biodiversity, environmental issues, and strategies for conservation.
| Chapter | Details Covered |
| Organisms and Populations | Population interactions, growth models, adaptations of organisms. |
| Ecosystem | Structure and function, productivity, food chain, food web, ecological pyramids, nutrient cycles. |
| Biodiversity and Conservation | Types of biodiversity, hotspots, threats, conservation methods (in-situ and ex-situ). |
| Environmental Issues | Air and water pollution, deforestation, global warming, ozone depletion, waste management. |
More Important Resources for CBSE Exam:
| CBSE Board: All details | CBSE Class 11 Commerce Subjects |
| CBSE Full Form | All about CBSE Class 11th |
| Class 11th Hornbill Syllabus |
Class 12 Biology Syllabus for Practicals (2025-26)
Total Marks: 30
Distribution of Marks:
| Component | Marks |
| One Major Experiment | 5 |
| One Minor Experiment | 4 |
| Slide Preparation | 5 |
| Spotting | 7 |
| Practical Record + Viva Voce | 4 |
| Project Record | 5 |
| Total | 30 |
List of Practicals in Biology Class 12 Syllabus
A. Experiments
- Prepare a temporary mount of onion root tip to study mitosis.
- Isolate DNA from available plant material such as spinach or green pea.
- Study the effect of different sugar solutions on egg plasma membrane (plasmolysis/osmosis experiment).
- Study of population density using the quadrat method (plants).
- Study the effect of salivary amylase on the rate of starch breakdown.
B. Slide Preparation
- Temporary slides of pollen germination.
- Study of permanent slides showing mitosis and meiosis stages.
- Preparation of temporary mount of stomata for study of density and distribution.
C. Spotting (7 Marks)
Identify and comment on:
- Flowers adapted for pollination (wind, insect).
- Diseased specimens (wheat rust, red rot of sugarcane, etc.).
- Common human parasites (Ascaris, liver fluke, malarial parasite).
- Biological specimens: Earthworm, cockroach, bony fish, bird, mammals.
- Prepared slides: DNA packaging, stages of gametogenesis, embryos of dicot/monocot seeds.
D. Project Work & Record
- Maintain a proper practical record notebook.
- Submit one investigatory project (environment, genetics, human health, biotechnology, biodiversity, etc.).
CBSE Class 12 Biology Syllabus: Question Paper Design
- Maximum Marks (Theory): 70
- Duration: 3 Hours
Typology of Questions:
| Type of Questions | Marks per Question | No. of Questions | Total Marks |
| Very Short Answer (VSA) / MCQs | 1 | 10 | 10 |
| Short Answer I (SA-I) | 2 | 5 | 10 |
| Short Answer II (SA-II) | 3 | 9 | 27 |
| Long Answer (LA) | 5 | 5 | 25 |
| Total | – | 29 | 70 |
Unit-Wise Weightage
| Unit | Marks |
| I. Reproduction | 14 |
| II. Genetics and Evolution | 18 |
| III. Biology and Human Welfare | 14 |
| IV. Biotechnology and Its Applications | 10 |
| V. Ecology and Environment | 14 |
| Total | 70 |
Internal Assessment (30 Marks)
- Practical Work – 15 Marks
- Project Record – 5 Marks
- Practical Record & Viva Voce – 5 Marks
- Class Test/Periodic Assessment – 5 Marks
Class 12 Biology Chapters List (2025-26)
| Unit | Chapters |
| Unit I: Reproduction | 1. Reproduction in Organisms 2. Sexual Reproduction in Flowering Plants 3. Human Reproduction 4. Reproductive Health |
| Unit II: Genetics and Evolution | 5. Principles of Inheritance and Variation 6. Molecular Basis of Inheritance 7. Evolution |
| Unit III: Biology and Human Welfare | 8. Human Health and Disease 9. Strategies for Enhancement in Food Production 10. Microbes in Human Welfare |
| Unit IV: Biotechnology and Its Applications | 11. Biotechnology – Principles and Processes 12. Biotechnology and Its Applications |
| Unit V: Ecology and Environment | 13. Organisms and Populations 14. Ecosystem 15. Biodiversity and Conservation 16. Environmental Issues |
Prescribed Books for CBSE Class 12th Biology Syllabus
The CBSE recommends NCERT textbooks as the main study resource. Students must study these thoroughly, as most board exam and NEET questions are based directly on them.
- Biology: Class XII, NCERT Publication
- Other References (optional): Trueman’s Biology, Pradeep’s Biology, or other practice books for additional MCQs and diagrams.
Objectives of CBSE Class 12 Biology Syllabus 2025-26
The Class 12 Biology syllabus has been framed to:
- Strengthen conceptual knowledge of advanced topics like genetics, biotechnology, evolution, and ecology.
- Develop practical and experimental skills through lab work, projects, and investigations.
- Prepare students for higher education and competitive exams such as NEET, AIIMS, and other medical/paramedical entrances.
- Promote awareness of health and environment by linking biology concepts with human welfare and ecological balance.
- Build analytical and application-based learning to understand processes like heredity, reproduction, and ecosystem functioning.
- Encourage scientific curiosity and research orientation among students for future studies in life sciences.
Check the latest CBSE Class 11 syllabus for all subjects below:
| Class 11th History Syllabus | Class 11th Chemistry Syllabus |
| Class 11th Legal Studies Syllabus | Class 11th Biology Syllabus |
| Class 11th Accountancy Syllabus | Class 11th Psychology Syllabus |
| Class 11th Entrepreneurship Syllabus | Class 11th Fine Arts Syllabus |
| Class 11th Business Studies Syllabus | Class 11th Sociology Syllabus |
| Class 11th Maths Syllabus | Class 11th Economics Syllabus |
| Class 11th Political Science Syllabus | Class 11th English Syllabus |
| Class 11th Physics Syllabus | Class 11th Hindi Syllabus |
| Class 11th Geography Syllabus | Class 11th Computer Science Syllabus |
| Class 11th Informatics Practices Syllabus | Class 11th Physical Education Syllabus |
| Class 11th Home Science Syllabus | Class 11th Sanskrit Syllabus |
Tips to Prepare for Class 12 Biology Syllabus
1. Prioritize NCERT Thoroughly
NCERT is the most important source for Class 12 Biology. Read each line carefully, highlight definitions, and revise in-text diagrams and flowcharts.
2. Master the Diagrams
Well-labeled diagrams can fetch full marks. Practice drawing human physiology systems, plant structures, and biotechnology processes regularly.
3. Focus on High-Weightage Units
Give extra time to Genetics, Evolution, and Human Welfare, as these carry the maximum marks in both boards and NEET.
4. Connect Theory with Practicals
Revise experiments side by side with related theory chapters. For example, while studying mitosis, revise onion root tip practical.
5. Create Chapter-Wise Notes
Prepare crisp notes with important terms, scientists’ names, and examples. Use flowcharts and mnemonics for quick memory recall.
6. Solve Previous Year Papers
Go through past board exam papers and sample papers. It helps you understand question types, marking scheme, and frequently repeated concepts.
7. Revise Regularly with Short Targets
Break the syllabus into weekly goals. Revise each unit at least 3–4 times before the exams. Consistency matters more than long study hours.
8. Practice Objective Questions for NEET
If preparing for NEET, solve NCERT-based MCQs daily. Biology has the highest weightage in NEET, and Class 12 chapters are heavily tested.
Suggested Project Topics for Class 12 Biology Syllabus
Students must complete one investigatory project as part of their practical assessment. Here are some engaging and scoring project ideas:
- DNA Fingerprinting Simulation: A study on its principles and applications in forensic science.
- Antibiotic Resistance in Bacteria: Observing the effect of antibiotics on bacterial growth (using safe lab strains).
- Study of GM Crops (Bt Cotton / Golden Rice): Benefits, risks, and ethical issues.
- Impact of Smoking and Alcohol on Human Health: Survey-based study with data analysis.
- Biofertilizers vs Chemical Fertilizers: Comparative effect on seed germination and growth.
- Study of Blood Groups and Rh Factor Distribution in a local community.
- Effect of Different Pollutants on Seed Germination Testing with smoke, detergents, or heavy metals.
- Biogas Production from Organic Waste: Observing efficiency of different substrates.
- Human Diseases Awareness Project: Case study of diseases like cancer, AIDS, malaria, or tuberculosis.
- Enzyme Activity Study: Effect of temperature, pH, or substrate concentration on enzyme action (like salivary amylase).
- Biodiversity Study in Local Area: Listing plant and animal diversity with ecological notes.
- Water Quality Testing: Checking pH, dissolved oxygen, and presence of pollutants in local water sources.
Read the chapter-wise summaries of Class 11 English here:
FAQs About Class 12th Biology Syllabus
There are 16 chapters divided into 5 units – Reproduction, Genetics & Evolution, Biology & Human Welfare, Biotechnology, and Ecology.
The Genetics and Evolution unit carries the maximum weightage of 18 marks.
Yes, NCERT is more than enough for boards. Most questions are directly based on it.
Around 6–8 major experiments along with slide preparation, spotting, and project work.
Yes, nearly 50% of NEET Biology questions come from the Class 12 syllabus.
Maintain neat records, prepare slides carefully, practice diagrams, and revise spotting examples thoroughly.
Many students find Molecular Basis of Inheritance (Unit II) challenging due to its detailed processes.
Reproduction is considered easier and more straightforward compared to others.
Ecology is very important, carrying 14 marks, and also helps in NEET preparation.
Find detailed questions and answers from all chapters of English Class 11 now:
Discover CLAT exam resources that can help you get started early:
Explore CLAT coaching centers across different cities: