Get ready for the boards with this comprehensive breakdown of the CBSE Class 12 Biology syllabus, including the class 12 biology syllabus chapter-wise, exam blueprint, marking scheme, practical Syllabus, and preparation strategy.
The goal of the CBSE Class 12 Biology Syllabus 2025 – 2026 is to help students better comprehend the study of biology while getting them ready for board exams and other assessments. The Syllabus ensures a proper combination of theory, practicals, and application-based learning, which covers interesting topics like genetics, evolution, biotechnology, and ecology. Let’s examine the comprehensive CBSE syllabus for 2025–2026 and the most effective study techniques if you’re prepared to dive into the field of biology and achieve high scores!
Competency-Based Question Paper Pattern: CBSE Class 12 Biology 2025 – 26
CBSE has designed the question paper pattern for CBSE Class 12 Biology to align with NEP‑2023 goals and newer Bloom’s taxonomy. The expected distribution is:
| S. No. | Bloom’s Taxonomy Category | Cognitive Level | Weightage (%) |
| 1 | Knowledge & Understanding | Easy Difficulty Level | 50% |
| 2 | Application | Medium Difficulty Level | 30% |
| 3 | Analysis, Evaluation, and Creation | Hard Difficulty Level | 20% |
| Total | 100% |
Class 12 Biology Marking Scheme & Blueprint for 2026 Exam
Here is the unit‑wise marks distribution for Class 12 Biology Theory and Practical
| Unit No. | CBSE Class 12 Biology Unit Name | Marks |
| VI | Reproduction | 16 |
| 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 Practical Marks Distribution
| CBSE Class 12 Biology Practical | Marks |
| One Major Experiment (Experiment No. 5) | 5 |
| One Minor Experiment (Experiment Nos. 2 & 3) | 4 |
| Slide Preparation (Experiment Nos. 1 & 4) | 5 |
| Spotting | 7 |
| Practical Record + Viva Voce (Credit may be given for consistent work over the academic session) | 4 |
| Investigatory Project + Project Record + Viva Voce | 5 |
| Total | 30 |
Complete Unit-wise Syllabus for CBSE Class 12 Biology 2025–26
This is the CBSE Class 12 Biology 2025 – 2026 unit-wise syllabus. It helps students focus their preparation on the most recent curriculum and exam blueprint by outlining the key ideas from every unit.
Class 12 Biology Unit VI: Reproduction (16 Marks)
Class 12 Biology Chapter 1: Sexual Reproduction in Flowering Plants
Covers flower structure, gametophyte development, types of pollination, pollen-pistil interaction, double fertilization, and post-fertilization events such as seed and fruit formation. Also includes apomixis, parthenocarpy, and polyembryony.
Class 12 Biology Chapter 2: Human Reproduction
Includes male and female reproductive systems, gametogenesis, menstrual cycle, fertilisation, embryo development up to blastocyst stage, implantation, pregnancy, placenta, parturition, and lactation (introductory concepts).
Class 12 Biology Chapter 3: Reproductive Health
Focuses on the need for reproductive health, prevention of STDs, birth control methods, contraception, medical termination of pregnancy (MTP), infertility, and assisted reproductive technologies (IVF, ZIFT, GIFT).
Class 12 Biology Unit VII: Genetics and Evolution (20 Marks)
Class 12 Biology Chapter 4: Principles of Inheritance and Variation
Covers Mendelian inheritance, deviations like incomplete dominance and co-dominance, polygenic inheritance, sex determination, linkage, crossing over, and genetic disorders such as haemophilia and thalassemia.
Class 12 Biology Chapter 5: Molecular Basis of Inheritance
Explains the discovery of genetic material, DNA/RNA structure and replication, transcription, translation, gene regulation (lac operon), genome projects, and DNA fingerprinting.
Class 12 Biology Chapter 6: Evolution
Discusses the origin of life, evidence of evolution, Darwin’s theory, modern synthetic theory, natural selection, genetic drift, gene flow, Hardy-Weinberg principle, adaptive radiation, and human evolution.
Class 12 Biology Unit VIII: Biology and Human Welfare (12 Marks)
Class 12 Biology Chapter 7: Human Health and Diseases
Covers pathogens and diseases such as malaria, typhoid, and pneumonia, immunity and vaccines, HIV/AIDS, cancer, and substance abuse.
Class 12 Biology Chapter 8: Microbes in Human Welfare
Focuses on the use of microbes in industries, food processing, sewage treatment, biocontrol agents, biofertilizers, and antibiotic production.
Class 12 Biology Unit IX: Biotechnology and its Applications (12 Marks)
Class 12 Biology Chapter 9: Biotechnology – Principles and Processes
Introduces genetic engineering and recombinant DNA technology.
Class 12 Biology Chapter 10: Biotechnology and Its Applications
Covers applications in agriculture and medicine, including human insulin, gene therapy, stem cells, Bt crops, transgenic animals, and biosafety issues.
Class 12 Biology Unit X: Ecology and Environment (10 Marks)
Class 12 Biology Chapter 11: Organisms and Populations
Focuses on ecological interactions like mutualism and predation, and population attributes like growth and age distribution.
Class 12 Biology Chapter 12: Ecosystem
Covers the structure and function of ecosystems, productivity, energy flow, and ecological pyramids.
Class 12 Biology Chapter 13: Biodiversity and Its Conservation
Explains biodiversity patterns, importance, threats, and conservation strategies, including hotspots, biosphere reserves, national parks, and Ramsar sites.
CBSE Class 12 Biology Practical Syllabus 2025 – 26
Here is the Practical Syllabus for Class 12 Biology 2025 – 26:
CBSE Class 12 Biology Practical A. List of Experiments in Class 12 Bio Syllabus 2026
- Prepare a temporary mount to observe pollen germination.
- Study the plant population density by the quadrat method.
- Study the plant population frequency by the quadrat method.
- Prepare a temporary mount of an onion root tip to study mitosis.
- Isolate DNA from available plant material such as spinach, green pea seeds, papaya, banana, etc.
CBSE Class 12 Biology Practical B. Study and observe the following (Spotting):
- Flowers adapted to pollination by different agencies (wind, insects, birds).
- Pollen germination on the stigma through a permanent slide or scanning electron micrograph.
- Identification of stages of gamete development, i.e., T.S. of testis and T.S. of ovary through permanent slides (from grasshopper/mice).
- Meiosis in onion bud cells or grasshopper testis through permanent slides.
- T.S. of blastula through permanent slides (Mammalian).
- Mendelian inheritance using seeds of different colours/sizes of any plant.
- Prepared pedigree charts of any one of the genetic traits, such as rolling of tongue, blood groups, ear lobes, widow’s peak, and colour blindness.
- Controlled pollination – emasculation, tagging, and bagging.
- Common disease-causing organisms like Ascaris, Entamoeba, Plasmodium, and any fungus causing ringworm through permanent slides, models, or virtual images or specimens. Comment on the symptoms of diseases that they cause.
- Models specimens showing symbiotic association in lichens, root nodules of leguminous plants, and the parasitic mode of nutrition shown by Cuscuta on its host.
- Flash cards/models showing examples of homologous and analogous organs.
CBSE Class 12 Biology Practical Items for Identification / Familiarity with Apparatus (For All Experiments)
- Glassware & Lab Tools: Beaker, Flask, Petri Plates, Test Tubes, Aluminium Foil, Paint Brush
- Materials: Soil samples (sandy, clayey, loamy), Small potted plants, Starch solution, Iodine, Ice cubes
- Heating Apparatus: Bunsen Burner / Spirit Lamp / Water Bath
- Biological Specimens & Models: Large flowers, Maize inflorescence, Model of frog developmental stages (morula and blastula),
Beads or seeds of various shapes, sizes, textures, Ascaris (model), Cactus / Opuntia (model)
CBSE Class 12 Biology Practical: List of Practicals
- Study of Floral Adaptations: Observation of flowers adapted for pollination by different agencies (wind, insects).
- Embryonic Development in Amphibians: Identification of the transverse section (T.S.) of the morula or blastula of the frog (using a model).
- Mendelian Inheritance Simulation: Study of Mendelian inheritance patterns using beads or seeds of varying textures and sizes.
- Pedigree Analysis: Preparation of pedigree charts showing traits like tongue rolling and colour blindness.
- Controlled Pollination Techniques: Hands-on practice of emasculation, tagging, and bagging.
- Pathogen Identification: Identification of common disease-causing organisms, such as Ascaris (model), with symptoms.
- Plant Adaptation Analysis: Commenting on morphological adaptations in plants found under xerophytic (dry) conditions
What’s New in CBSE Class 12 Biology Syllabus 2025–26?
The CBSE Class 12 Biology syllabus 2025–26 has been updated to reflect the latest academic expectations under NEP 2023. These changes enhance conceptual clarity and align more closely with competitive exams like NEET. Students should ensure they refer to the revised Syllabus rather than relying on outdated versions.
By downloading the class 12 biology syllabus PDF, students can:
- Avoid studying topics excluded from the latest 12th CBSE biology syllabus, saving valuable preparation time.
- Map each chapter from the NCERT textbook to the official biology class 12 syllabus chapter-wise.
- Prioritise units like Genetics and Evolution, Biotechnology, and Ecology, which carry more weight and are crucial for exams.
- Understand the updated breakdown of practicals, viva, project work, and theory for the bio CBSE class 12.
- Align their preparation with the competency-based question pattern now emphasized by CBSE.
- Stay focused on scoring areas instead of spending time on obsolete material.
- Prepare effectively for internal assessments by knowing the exact practical components and record requirements.
- Use the 12th biology syllabus to filter and practice the most relevant NCERT exemplar questions and case-based problems.
- Accessing the CBSE class 12 biology syllabus 2025–26 streamlines your board exam prep and helps you cover all high-priority NEET topics without confusion.
How to Prepare for CBSE Biology Class 12 Effectively
- Understand the Syllabus Thoroughly: For clarity, go over each unit in the biology class 12 syllabus chapter by chapter after downloading the official biology syllabus in PDF format. Determine the blueprint’s unit-wise markings and make appropriate plans.
- Plan Weekly Targets & Stick to Timelines: Divide the Syllabus into chapters or units. Reproduction and Genetics in Month 1, Biotech and Welfare in Month 2, and Ecology and Revision in Month 3.
- Practice Diagrams, Labelling & Definitions: The reproductive system, DNA, immune response, and ecological pyramid are all high-scoring diagrams. By the 12th CBSE biology syllabus format, label clearly and practice the NCERT definitions line by line.
- Use Revision Notes & Flashcards: Mendelian ratios, biotechnological tools, reproductive stages, types of ecological succession. It’s recommended by CBSE-friendly practices within the biochemistry class 12 portion preparation.
- Solve Sample Papers, PYQs & Case‑Based Questions: Use CBSE sample papers and previous year question papers (PYQs) that follow the competency-based question paper pattern. Practice case-based and data interpretation questions to target application and evaluation skills.
The CBSE Class 12 Biology Syllabus 2025 – 26 offers a well-balanced mix of theoretical knowledge and practical skills, ensuring readiness for board exams and competitive tests like NEET.
FAQs on CBSE Class 12 Biology Syllabus 2025 – 26
Q1. Is there any reduction in the Class 12 Biology syllabus this year?
Some chapters, such as parts of Food Production and Organisms & Populations, have reduced content as per the chemistry class 12 term two syllabus pattern. CBSE has issued an updated, reduced section in the official Class 12 Biology syllabus PDF
Q2. Are NCERT books enough to cover the CBSE Biology syllabus?
Absolutely. NCERT textbooks align fully with the official 12th biology syllabus, including all theory and diagrams. Additional practice should be drawn from CBSE sample papers or supplementary study material.
Q3. How many marks are allotted for practicals in Biology Class 12?
According to the 12th CBSE biology syllabus marking scheme, practicals consist of major and minor experiments, spotting, slide preparation, record work, and a viva/investigatory project. They are worth a total of 30 marks.
Q4. Which chapters are most important for the CBSE Biology board exam?
High-priority subjects include Biology in Human Welfare (12), Reproduction (16), Genetics & Evolution (20), and Biotechnology (12). Ecology (10) should also not be overlooked, particularly regarding illustrations and concerns involving the chain of causation.
Q5. Where can I get the official syllabus PDF?
The Class 12 Biology syllabus PDF download is available on the CBSE academic website (cbseacademic.nic.in).
Stay tuned with iScholar for more expert tips, CBSE Class 12, and study strategies to help you succeed in your learning journey!
