The Council for the Indian School Certificate Examinations (CISCE) has made the detailed ISC Class 12 Biology Syllabus 2025-26 available. The syllabus includes two papers - Theory (70 marks) and Practical (30 marks, inclusive of project and file work). The CISCE syllabus effectively cultivates deeper understanding about biological principles, understanding and skills in the laboratory, as well as applications to health and industry, agriculture, and the environment.
ISC Class 12 Biology Syllabus 2025-26 PDF Download
Students can download the official PDF of ISC Biology Syllabus 2025-26 from the CISCE academic website or from the provided link:
Download ISC Biology Syllabus 2025-26 PDF Here
Overview of ISC Biology Class 12 Exam 2025-26
| Paper | Description | Duration | Marks |
| Paper I | Theory | 3 Hours | 70 Marks |
| Paper II | Practical (Project + File Work) | – | 30 Marks |
ISC Class 12 Biology Theory Syllabus 2025-26 (Paper I – 70 Marks)
The theory paper includes five major units as shown below:
| S. No. | Unit | Marks |
| 1 | Reproduction | 16 |
| 2 | Genetics and Evolution | 15 |
| 3 | Biology and Human Welfare | 14 |
| 4 | Biotechnology and Its Applications | 10 |
| 5 | Ecology and Environment | 15 |
| Total | – | 70 |
ISC Class 12 Biology 2025-26: Unit-wise Topics Table
| Unit No. | Unit Title | Key Topics Covered |
| 1 | Reproduction | - Sexual reproduction in flowering plants (pollination, fertilisation, seed/fruit formation) - Human reproduction (male/female reproductive systems, gametogenesis, menstrual cycle, pregnancy) - Reproductive health: STDs, contraceptives, infertility, ART, MTP, amniocentesis |
| 2 | Genetics and Evolution | - Mendelian inheritance, polygenic traits, pedigree analysis - DNA: structure, replication, transcription, genetic code, translation, lac operon - Human Genome Project, DNA fingerprinting - Origin of life, Darwinism, Hardy-Weinberg principle, human evolution |
| 3 | Biology and Human Welfare | - Human diseases: Infections, cancer, AIDS, vaccination, immunity - Drug and alcohol abuse - Microbes in human welfare: household use, industries, biofertilisers, antibiotics, sewage treatment |
| 4 | Biotechnology | - Recombinant DNA technology, restriction enzymes, PCR, vectors, cloning - Applications: GM crops, insulin, gene therapy, transgenic animals - Biosafety, biopiracy, biopatents |
| 5 | Ecology and Environment | - Population: growth, interactions, adaptations - Ecosystems: structure, energy flow, food chains, productivity, decomposition - Biodiversity, conservation strategies, extinction, hotspots, Red Data Book, Ramsar sites |
ISC Biology Practical Syllabus 2025-26 (Paper II – 30 Marks)
Marks Distribution
| Component | Marks |
| Project Work | 10 |
| Practical File | 5 |
| Laboratory Work (Experiments, Spotting, Slide Prep) | 15 |
| Total | 30 |
ISC 12th Biology Key Practical Areas
| Category | Topics |
| Taxonomy | Dissection and diagram of families: Malvaceae, Papilionaceae, Solanaceae, Liliaceae, Cruciferae, Compositae, Gramineae |
| Biochemical Experiments | Stomatal study, soil texture/pH analysis, enzyme activity at various temperatures/pH |
| Slide Preparation | Pollen germination, T.S. of ovary (placentation), hydrophyte stem, xerophyte leaf |
| Spotting | Human reproductive organs, stages of embryo, malaria parasite, adaptations, pollination types |
| DNA Isolation | From banana, papaya, spinach etc. using ethanol method |
ISC Class 12 Biology Project Work (10 Marks)
Students must complete one investigatory project. Handwritten original work is preferred.
Suggested Topics:
- Genetic disorders, gene therapy, genome project
- AIDS, cancer, drug addiction
- Microorganisms in industry
- Mendelian inheritance
- Environmental resistance
- Pest control methods
- Role of agrochemicals
Assessment Criteria:
- Content accuracy
- Presentation with visuals (graphs, charts)
- Analysis and conclusion
- Bibliography
Scientists and Their Contributions
| Scientist | Contribution |
| Darwin | Theory of Natural Selection |
| Mendel | Laws of Inheritance |
| Watson & Crick | Structure of DNA |
| Hershey & Chase | DNA is genetic material |
| Miescher | Discovery of nuclein (DNA) |
| Jacob & Monod | Lac operon |
| Alec Jeffreys | DNA fingerprinting |
| Chargaff | Base-pairing rules |
| Miller & Urey | Experiment on origin of life |
| Sanger | DNA sequencing |
(Full list includes 35+ scientists from ecology, genetics, and molecular biology)
Important Abbreviations in ISC Biology
| Abbreviation | Full Form |
| ADA | Adenosine Deaminase |
| CMI | Cell Mediated Immunity |
| EST | Expressed Sequence Tags |
| GMO | Genetically Modified Organism |
| GPP | Gross Primary Productivity |
| ICSI | Intra Cytoplasmic Sperm Injection |
| PCR | Polymerase Chain Reaction |
| RCH | Reproductive and Child Health |
| SCID | Severe Combined Immunodeficiency |
| VNTR | Variable Number Tandem Repeats |
(More than 30 abbreviations are included in the syllabus)
ISC 12th Biology Exam 2026 Preparation Tips
- Learn the diagram and terminology by practicing with labelling.
- Explore reproductive and molecular biology through concept maps.
- Frequently practice solving genetics problems and pedigree problems.
- Complete project and practical files in time.
- Make sure to revise the scientists and abbreviations using flashcards.
Also read: ISC 12th Preparation Tips 2026
