For students preparing for the Karnataka 2nd PUC Biology board exams in 2025-26, the complete syllabus is now accessible online, offering a clear roadmap for success. This article details the structure of the examination, chapter-wise mark distribution, and crucial topics, empowering students to prepare effectively and thoroughly.
Karnataka 2nd PUC Biology Examination 2026
The Karnataka 2nd PUC Biology examination is a comprehensive assessment totaling 100 marks. This total is split into a 70-mark theory exam and a 30-mark practical exam. The theory paper will feature a variety of question types, including objective-type, very short answer-type, short answer-type, and long answer-type questions. To successfully pass the subject, students must achieve a minimum of 35% overall, which translates to at least 24 marks in the 80-mark theory paper.
The syllabus encompasses 13 chapters, each meticulously divided into distinct sub-topics to ensure in-depth coverage. Students are advised to cover each topic in detail to build a strong foundation.
Karnataka 2nd PUC Biology Marking Scheme 2025-26
Students can utilize the latest Marking Scheme provided below to understand the weightage of each chapter from the 2nd PUC Biology syllabus for 2026 exams:
| Chapter | No. of Periods | Marks |
| 1. Sexual reproduction in flowering plants | 12 | 11 |
| 2. Human reproduction | 11 | 10 |
| 3. Reproductive health | 7 | 6 |
| 4. Principles of Inheritance | 15 | 13 |
| 5. Molecular basis of Inheritance | 15 | 13 |
| 6. Evolution | 8 | 7 |
| 7. Human health and disease | 13 | 11 |
| 8. Microbes in Human welfare | 8 | 7 |
| 9. Biotechnology: Principles and Processes | 8 | 7 |
| 10. Biotechnology and its applications | 7 | 6 |
| 11. Organism and population | 6 | 6 |
| 12. Ecosystem | 5 | 4 |
| 13. Biodiversity and Conservation | 5 | 4 |
| Total | 120 | 105 |
Based on this table, the chapters with the highest weightage include Molecular Basis of Inheritance, Principle of Inheritance, Human Health and Disease, Sexual Reproduction in Plants, and Human Reproduction.
Karnataka 2nd PUC Biology Syllabus 2026: Detailed Syllabus
| Chapter | Title | Topics Covered |
| 1 | Sexual reproduction in flowering plants | - Flower structure, male and female gametophyte development - Types and agents of pollination - Outbreeding devices - Pollen-pistil interaction, double fertilization - Post-fertilization events: endosperm, embryo, seed and fruit formation - Apomixis, parthenocarpy, polyembryony - Significance of seed dispersal and fruit formation |
| 2 | Human reproduction | - Male and female reproductive systems - Microscopic structure of testis and ovary - Gametogenesis: spermatogenesis, oogenesis - Menstrual cycle, fertilization - Embryo development to blastocyst stage - Implantation, pregnancy, placenta formation - Parturition and lactation (elementary ideas) |
| 3 | Reproductive health | - Importance of reproductive health - Birth control methods and their significance - Medical Termination of Pregnancy (MTP), amniocentesis - Prevention of STDs - Infertility and assisted reproductive technologies (IVF, ZIFT, GIFT) – basic awareness |
| 4 | Principles of Inheritance and Variation | - Heredity and variation - Mendelian inheritance and deviations (incomplete dominance, co-dominance, multiple alleles, blood groups) - Pleiotropy and polygenic inheritance - Chromosome theory of inheritance - Chromosomal disorders: Down's, Turner's, Klinefelter's syndrome |
| 5 | Molecular basis of Inheritance | - DNA as genetic material - DNA and RNA structure - DNA packaging, replication, central dogma - Transcription, genetic code, translation - Gene expression, regulation (lac operon) - Genome projects, DNA fingerprinting |
| 6 | Evolution | - Origin of life and biological evolution - Evidences: palaeontology, anatomy, embryology, molecular - Darwin’s theory, Modern Synthetic Theory - Variation (mutation and recombination), natural selection - Types of natural selection - Gene flow, genetic drift, Hardy-Weinberg principle - Adaptive radiation, human evolution |
| 7 | Human health and diseases | - Disease prevention and control methods - Immunology basics - Cancer, HIV/AIDS, vaccination - Alcohol and drug abuse in adolescence |
| 8 | Microbes in Human Welfare | - Microbes in food processing, industry, sewage treatment, energy production - Role as biocontrol agents and biofertilizers - Antibiotics: production and responsible usage |
| 9 | Biotechnology – Principles and Processes | - Genetic modification principles - Recombinant DNA technology |
| 10 | Biotechnology and its applications | - Applications in health and agriculture - Human insulin, vaccine production, stem cell research - Gene therapy, GMOs (Bt crops, transgenic animals) - Biosafety, biopiracy, biopatents |
| 11 | Organism and populations | - Habitat and niche concepts - Ecological adaptations - Population interactions: parasitism, predation, competition, mutualism - Population growth, mortality, age distribution |
| 12 | Ecosystem | - Ecosystem structure and components - Productivity and decomposition - Energy flow and ecological pyramids - Types of ecological pyramids - Population biology |
| 13 | Biodiversity and its Conservation | - Biodiversity loss and conservation strategies - Biodiversity hotspots - Endangered species, extinction - Red Data Book - Biosphere reserves, national parks, sanctuaries, Ramsar sites |
Karnataka 2nd PUC Biology Deleted Syllabus 2025-26
Students can refer to the deleted topics or chapters of the reduced Karnataka 2nd PUC Biology Syllabus 2025-26:
| Chapters | Page Number | Deleted Topics |
| Chapter 1: Reproduction in Organisms | 3–18 | Full Chapter |
| Chapter 9: Strategies for Enhancement in Food Production | 165–176, 178 | Full Chapter |
| Chapter 13: Organisms and Populations | 220 | 13.1 Organism and Its Environment |
| 221–222 | 13.1.1 Major Abiotic Factors | |
| 223–225 | 13.1.2 Responses to Abiotic Factors | |
| 225–226 | 13.1.3 Adaptations | |
| Ques. 1–3, 9–12 | Questions | |
| Chapter 14: Ecosystem | 250–252 | 14.6 Ecological Succession |
| 253–254 | 14.6.1 Succession of Plants | |
| 254–255 | 14.7 Nutrient Cycling | |
| 255 | 14.7.1 Carbon Cycle, 14.7.2 Phosphorus Cycle | |
| 14.8 Ecosystem Services | ||
| Chapter 16: Environmental Issues | 270–286 | Full Chapter |
Karnataka 2nd PUC Biology Exam Preparation Tips
- Students should aim to complete the 2nd PUC Biology chapters list 2026 early to ensure ample time for revision.
- Revision can be optimized by solving model test papers available online.
- Students are encouraged to practice previous year’s question papers for a better understanding of the exam pattern.
- Following a well-structured study plan is highly recommended to finish the syllabus on time.
- After finishing the syllabus, students must focus on practicing the Karnataka 2nd PUC Biology Model Papers to boost preparation and confidence.
