The Central Board of Secondary Education (CBSE) has released the detailed syllabus for Class 12 Biology (Code 044) for the academic year 2025–26. Students appearing for the CBSE 12th board exams in 2026 can refer to the updated syllabus that includes the unit-wise chapter breakdown, marks distribution, practical structure, and exam pattern. This helps students align their preparation with board requirements and identify the most scoring chapters.
In this article, you’ll find the complete syllabus for theory and practicals, including chapter-wise topics and assessment design. Students can also download the CBSE 12th Biology Syllabus 2026 PDF from the official CBSE website at cbseacademic.nic.in.
CBSE 12th Biology Syllabus 2026 PDF Direct Link
Click here to download CBSE Class 12 Biology Syllabus 2025-26 PDF
CBSE Class 12 Biology 2026: Unit-wise Marks Distribution
The Biology theory paper will be of 70 marks, with a duration of 3 hours. The remaining 30 marks are allotted for practicals.
| Unit No. | Title | Marks |
| VI | Reproduction | 14 |
| VII | Genetics and Evolution | 20 |
| VIII | Biology and Human Welfare | 12 |
| IX | Biotechnology and its Applications | 12 |
| X | Ecology and Environment | 10 |
| Total (Theory) | 70 |
CBSE Class 12 Biology Chapters and Topics 2026
| Unit | Chapter | Key Topics |
| VI | Sexual Reproduction in Flowering Plants | Flower structure, gametophyte development, pollination types, fertilization, seed and fruit formation, apomixis, parthenocarpy |
| Human Reproduction | Reproductive systems, gametogenesis, menstrual cycle, fertilization, implantation, placenta, parturition | |
| Reproductive Health | STD prevention, birth control methods, MTP, infertility, IVF, GIFT, ZIFT (general awareness) | |
| VII | Principles of Inheritance and Variation | Mendelian inheritance, codominance, blood groups, sex determination, linkage, genetic disorders (thalassemia, Down’s, Turner’s syndromes) |
| Molecular Basis of Inheritance | DNA structure, replication, transcription, translation, genetic code, genome projects, DNA fingerprinting | |
| Evolution | Biological evolution, Darwin’s theory, types of selection, gene flow, genetic drift, Hardy-Weinberg principle, human evolution | |
| VIII | Human Health and Diseases | Diseases: malaria, dengue, typhoid, AIDS; basics of immunology, cancer, HIV, drug and alcohol abuse |
| Microbes in Human Welfare | Microbes in food industry, sewage treatment, biocontrol, biofertilizers; antibiotics and their use | |
| IX | Biotechnology: Principles and Processes | Genetic engineering, recombinant DNA technology |
| Biotechnology and Its Applications | Applications in health and agriculture: insulin, vaccines, gene therapy, Bt crops, transgenic animals, biosafety, biopiracy, patents | |
| X | Organisms and Populations | Population interactions (mutualism, predation, etc.), growth patterns, birth/death rates |
| Ecosystem | Components, productivity, decomposition, energy flow, ecological pyramids (number, biomass, energy) | |
| Biodiversity and Conservation | Biodiversity concepts, conservation methods, hotspots, endangered species, Red Data Book, national parks, sanctuaries, Ramsar sites |
CBSE Class 12 Biology Practical Exam 2026 (30 Marks)
The practicals will be conducted for 30 marks with a duration of 3 hours. The assessment includes experiments, spotting, viva, and record evaluation.
Marking Scheme
| Component | Marks |
| One Major Experiment | 5 |
| One Minor Experiment | 4 |
| Slide Preparation | 5 |
| Spotting | 7 |
| Practical Record + Viva Voce | 4 |
| Investigatory Project + Viva Voce | 5 |
| Total | 30 |
CBSE Class 12 Biology Practical Experiments 2025–26
| Category | Experiment |
| A. Major/Minor Experiments | |
| 1. | Prepare a mount to observe pollen germination |
| 2. | Study plant population density using the quadrat method |
| 3. | Determine frequency of plant species via quadrat method |
| 4. | Observe mitosis in onion root tip through mount preparation |
| 5. | Isolate DNA from plant materials like spinach, peas, or banana |
| B. Spotting and Observation | (Any 5–7 to be done) |
| 1. | Identify flowers adapted for pollination by wind, insects, or birds |
| 2. | Observe pollen germination on stigma through a permanent slide |
| 3. | Identify gamete development stages (T.S. of testis/ovary) using permanent slides |
| 4. | Study meiosis in onion bud cells via permanent slides |
| 5. | Observe mammalian blastula stage (T.S. slide) |
| 6. | Study Mendelian traits using seeds of different colours/sizes |
| 7. | Create pedigree charts (e.g., tongue rolling, blood groups, color blindness) |
| 8. | Perform emasculation, tagging and bagging to demonstrate pollination control |
| 9. | Identify disease-causing organisms (e.g., Ascaris, Entamoeba, Ringworm) and their symptoms |
| 10. | Identify symbiotic relationships (e.g., lichens, leguminous root nodules, Cuscuta) |
| 11. | Differentiate homologous and analogous organs using models or flashcards |
Biology Practicals for Visually Impaired Students (Special Guidelines)
| Component | Marks |
| Identification of Apparatus | 5 |
| Written Practical Test | 10 |
| Practical Record File | 10 |
| Viva Voce | 5 |
| Total | 30 |
These students are assessed on alternative methods such as models, written questions, and simplified experiments using models and images.
CBSE Class 12 Biology 2026 Question Paper Design
| Competency | Weightage |
| Knowledge & Understanding | 50% |
| Application of Concepts | 30% |
| Analysis, Evaluation, and Creation | 20% |
CBSE 12th Biology Question Types
- Multiple Choice Questions (MCQs)
- Assertion & Reasoning
- Short Answer (SA)
- Long Answer (LA-I, LA-II)
- Case/Source-based questions
Note: 33% internal choice will be available in all sections.
CBSE Class 12 Biology Prescribed Books
- NCERT Biology – Class 12
- NCERT Multimedia and Supplementary Material
- CBSE Biology Lab Manual
The CBSE Class 12 Biology Syllabus 2026 is thoughtfully structured to promote conceptual clarity and practical application. Students are encouraged to focus on high-weightage units like Genetics and Evolution and Reproduction, and reinforce their understanding through lab-based learning.
For better exam preparation, download the CBSE 12th Biology Syllabus 2026 PDF, practice previous year papers, and stay updated with changes through the official CBSE website.
