CBSE Class 12 Biology Syllabus 2025-26 Download PDF, Marks Distribution
Vikas Pandit18 Dec, 2025
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CBSE Class 12 Biology Syllabus 2025-26: The CBSE Class 12 Biology Syllabus has been published by the Central Board of Secondary Education.
Students may use the provided link to obtain the most recent CBSE Class 12 Biology Syllabus PDF. They may also get the CBSE Class 12 Biology Syllabus 2025-26 from the official website, cbseacademic.nic.in.
The CBSE biology class 12 syllabus includes all of the modules, chapters, and topics for the theoretical test, as well as the specifics for the practicals.CBSE Class 12 Biology Syllabus Highlights
The Biology syllabus Class 12 CBSE 2025-26 is structured into five main units. Each unit carries a specific weightage. This clear structure helps students prioritize their studies.
| CBSE Class 12 Biology Syllabus Highlights | ||
|---|---|---|
| Unit | Title | 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 | 70 | |
Biology Syllabus Class 12 CBSE 2025-26 PDF
The CBSE Class 12 Biology Syllabus for the academic year 2025-26 is an important resource for students studying Biology. This syllabus outlines the topics and concepts that students will cover throughout the academic year. Understanding the syllabus helps students plan their study schedule effectively, allocate time for each topic, and ensure comprehensive learning. With the PDF link provided below, students can easily download and refer to the CBSE Class 12 Syllabus whenever needed. This enables students to stay organized, track their progress, and prepare thoroughly for their Biology classes and examinations.CBSE Class 12 Biology Syllabus 2025-26 PDF
CBSE Class 12 Biology Deleted Syllabus
The board decided to keep the 30% cut in the Biology curriculum for the CBSE Class 12 Exams. Students may get the updated syllabus PDF by visiting the official website at cbseacademic.nic.in.
CBSE Class 12 Biology Syllabus has 5 units in total. The theoretical portion is worth 70 points, while the practical portion is worth 30 points. The examination lasts three hours.
| CBSE Class 12 Biology Deleted Syllabus | |||
| Units | Chapters | Pages | Deleted Topics |
| Unit-VI - Reproduction | Chapter 1: Reproduction in Organisms | 3-18 | The whole chapter deleted |
| Unit-VIII - Biology and Human Welfare | Chapter 9: Strategies for Enhancement in Food Production | 165–176, 178 | The whole chapter deleted |
| Unit-X - Ecology and Environment | Chapter 13: Organisms and Populations | 220 221–222 223–225 225–226 250–252 253–254 254–255 255 | 13.1 Organism and Its Environment
|
| Chapter 14: Ecosystem | 14.6 Ecological Succession
|
||
| Chapter 16: Environmental Issues | 270–286 | Full Chapter | |
Biology Syllabus class 12 CBSE 2025-26 Chapter-Wise
This section covers the in-depth information of the Biology of Chemistry class 12 CBSE 2025-26.
It lists the chapters and key topics within each unit. The Class 12 Biology curriculum includes both theory and practical components. It focuses on conceptual understanding and application.
Unit VI: Reproduction
Chapter 1: Sexual Reproduction in Flowering Plants
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Flower structure; male and female gametophyte development.
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Pollination types, agencies, examples; out-breeding devices.
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Pollen-pistil interaction; double fertilization.
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Post-fertilization events: endosperm, embryo, seed, fruit formation.
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Special modes: apomixis, parthenocarpy, polyembryony.
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Significance of seed dispersal and fruit formation.
Chapter 2: Human Reproduction
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Male and female reproductive systems.
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Microscopic anatomy of testis and ovary.
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Gametogenesis: spermatogenesis and oogenesis.
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Menstrual cycle; fertilization, embryo development (blastocyst).
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Implantation; pregnancy, placenta formation (elementary).
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Parturition (elementary idea).
Chapter 3: Reproductive Health
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Need for reproductive health; STD prevention.
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Birth control: need and methods, contraception.
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Medical Termination of Pregnancy (MTP); amniocentesis.
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Infertility and Assisted Reproductive Technologies (IVF, ZIFT, GIFT).
Unit VII: Genetics and Evolution
Chapter 4: Principles of Inheritance and Variation
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Heredity and variation; Mendelian inheritance.
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Deviations from Mendelism: incomplete dominance, co-dominance, multiple alleles.
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Inheritance of blood groups, pleiotropy; polygenic inheritance (elementary).
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Chromosome theory of inheritance; chromosomes and genes.
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Sex determination (humans, birds, honey bee).
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Linkage and crossing over; sex-linked inheritance (haemophilia, colour blindness).
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Mendelian disorders (thalassemia); chromosomal disorders (Down's, Turner's, Klinefelter's).
Chapter 5: Molecular Basis of Inheritance
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Search for genetic material; DNA as genetic material.
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Structure of DNA and RNA; DNA packaging.
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DNA replication; Central Dogma.
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Transcription, genetic code, translation.
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Gene expression and regulation: lac operon.
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Genome, Human and rice genome projects; DNA fingerprinting.
Chapter 6: Evolution
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Origin of life; biological evolution and evidences (paleontology, comparative anatomy, embryology, molecular).
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Darwin's contribution; modern synthetic theory of evolution.
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Mechanism of evolution: variation (mutation, recombination), natural selection.
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Examples of natural selection types; Gene flow, genetic drift.
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Hardy-Weinberg's principle; adaptive radiation; human evolution.
Unit VIII: Biology and Human Welfare
Chapter 7: Human Health and Diseases
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Pathogens; parasites causing human diseases (malaria, dengue, typhoid, pneumonia, common cold, amoebiasis, ringworm).
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Disease control; Basic immunology: vaccines.
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Cancer, HIV and AIDS; Adolescence: drug and alcohol abuse.
Chapter 8: Microbes in Human Welfare
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Microbes in food processing, industrial production, sewage treatment.
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Energy generation; microbes as biocontrol agents and bio-fertilizers.
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Antibiotics: production and judicious use.
Unit IX: Biotechnology and Its Applications
Chapter 9: Biotechnology - Principles and Processes
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Genetic Engineering (Recombinant DNA Technology).
Chapter 10: Biotechnology and Its Applications
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Applications in health and agriculture.
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Human insulin, vaccine production, stem cell technology, and gene therapy.
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Genetically Modified Organisms: Bt crops; transgenic animals.
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Biosafety issues, biopiracy, and patents.
Unit X: Ecology and Environment
Chapter 11: Organisms and Populations
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Population interactions: mutualism, competition, predation, parasitism.
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Population attributes: growth, birth rate, death rate, age distribution.
Chapter 12: Ecosystem
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Ecosystems: patterns, components.
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Productivity and decomposition; energy flow.
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Pyramids of number, biomass, energy.
Chapter 13: Biodiversity and Its Conservation
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Biodiversity: concept, patterns, importance.
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Loss of biodiversity; biodiversity conservation.
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Hotspots, endangered organisms, and extinction.
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Red Data Book, Sacred Groves, biosphere reserves, national parks, wildlife sanctuaries, Ramsar sites.
CBSE Class 12 Biology Syllabus 2025-26 Practicals Marking Scheme
Every CBSE student knows how important the class 12 board examinations are, as the results play an important role in their academic progress and are a major factor in gaining admission to universities.Students must be fully informed on the most recent syllabus for each subject to perform successfully. The CBSE Biology Practical Class 12 grading structure is shown below:
|
CBSE Class 12 Biology Syllabus Practicals Marking Scheme |
|
| Evaluation Component | Marks |
| One Major Experiment | 5 |
| One Minor Experiment (Experiments 2 & 3) | 4 |
| Slide Preparation (Experiment 1 & 4) | 5 |
| Spotting | 7 |
| Practical Record + Viva Voce | 4 |
| Investigatory Project + Project Record + Viva Voce | 5 |
| Total | 30 |
CBSE Class 12 Biology Practical Deleted Syllabus
In order to save time and avoid using it during exam preparation, students should be informed of the removal Biology syllabus for class 12.|
CBSE Class 12 Biology Syllabus Practical Deleted Syllabus |
||
| Part | Particulars | Deleted Practicals |
| A | List of Experiments | 2. Collect and study soil from at least two different sites and study them for texture, moisture content, pH, and water-holding capacity. Correlate with the kinds of plants found in them. 3. Collect water from two different water bodies around you and study them for pH, clarity and presence of any living organism. 4. Study the presence of suspended particulate matter in the air at two widely different sites. 8. Study the effect of different temperatures and three different pH on the activity of salivary amylase on starch. |
| B | Study/observation of the following (Spotting) | 10. Two plants and two animals (models/virtual images) were found in xeric conditions. Comment upon their morphological adaptations. 11. Two plants and two animals (models/virtual images) found in aquatic conditions. Comment on their morphological adaptations. |
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