The Bihar School Examination Board (BSEB) provided the biology class 12 syllabus bihar board 2025 for Science students. They can check and download the Biology syllabus in the pdf format. All the chapters included in the syllabus are mentioned in detail along with the marks provided to each of them. Among all units, Genetics and organic evolution, Biotechnology and its applications, and Applied biology and human welfare carry the most marks. All the units will be marked for 18 marks. The students should pay attention to each of the chapters in order to prepare the questions. Also, go through the Bihar Board 12th exam pattern 2026 to know the types of questions appearing in the board exams.
DownloadBihar Board Class 12 Biology Syllabus 2025-26 here
Bihar Board Class 12 Biology Syllabus 2025-26: Course Structure
Check the class 12th biology syllabus bihar board 2026 from the table below:
Unit | Unit Name | Marks |
Unit 1 | Reproduction and development | 06 |
Unit 2 | Genetics and organic evolution | 18 |
Unit 3 | Biotechnology and its applications | 18 |
Unit 4 | Applied biology and human welfare | 18 |
Unit 5 | Man and environment | 10 |
Bihar Board Class 12 Biology Syllabus 2025-26: Chapter-wise
As mentioned earlier, there are a total of 16 chapters in the 12th biology syllabus bihar board. The chapter-wise class 12 biology bihar board syllabus is provided below:
Unit 1 - REPRODUCTION AND DEVELOPMENT
- Reproduction in Plants - Types of reproduction, reproductive part of flower gametogenesis, pollination and fertilization; Development of seeds and fruits..
- Reproduction and development in Human - Reproductive system in male and female Role of sex-hornones in the development of sexual characters, menstrual cycle production of gametes (gametogenesis), fertilization, implantation, embryo development, pregnancy and parturation, Test-tube baby (IVF).
- Reproduction Health - Birth control, contraception and sexually transmitted diseases
Unit II - GENETICS AND ORGANIC EVOLUTION
- Introduction
- Mendelism - Mendel's experiments of monohybrid and dihybrid cross, Mendel's law of inheritance.
- Gene interaction - Incomplete dominance, co-dominance, multiple alleles (blood groupings), Epistasis.
- Chromosome theory of inheritance, linkage and crossing over, cytoplasmic inheritance.
- Sex-determination in human beings: XX, Xy, Sex-linked inheritance and cogenital diseases ex. Haemophilia, colour blindness, Sickle celled anaemia.
- Elementary idea of Gene, chromatin fibre and chromosome.
- DNA - replication, Genetic code, transcription and translation.
- Gene expression and regulation
- Mechanism of variation - at chromosome level (chromosomal abberation and its gene level (mutation).
- Theories and evidence of organic evolution, Lamarckism, Darwinism and Neo-Darwinism.
UNIT-III - BIOTECHNOLOGY AND HIS APPLICATIONS
- Elementary idea of components of Biotechnology.
- Tools and techniques.
- Recombinant DNA technology, Genetically modified (GM) organism-Appicea
- in health, Agriculture and Industries.
- Insulin and BT-Cotton.
UNIT-IV : APPLIED BIOLOGY AND HUMAN WELFARE
- Introduction - Elementary idea of animal husbandry, poultry, fisheries, silviculture (litchi, n Horticulture, Apiculture, Sericulture, Cultivation of Makhana and Medicinal p Improvement in agriculture, food production and food processing, food probe and micro organisms.
- Basic concepts of plant breeding and tissue culture.
- Microbes in sewage treatment and energy generation.
- Basic concept of Immunology, vaccines.
- Parasites and pathogens.
- Cancer and AIDS
- Adolescence and drug / alcohol abuse.
UNIT V - MAN AND ENVIRONMENT
- Effect of increasing population on Ecosystem.
- Conservation of biological resources - Wildlife and forest conservation. Importance of forests, hazards of deforestation, afforestation, Indian forests; causes for extinction of some wild life. Concept of endangered species, Measures and steps for conservation of endangered species.
Environmental Issues -
- Environmental pollution; Air pollution, water pollution, soil pollution, noise pollution, radiation pollution, their effects and methods of control.
- Environmental laws.
PRACTICAL CLASSES FOR CLASS - XII
Major Experiments:
(i) Study the reproducing part of different flowers.
(ii) Study of flowers adapted to pollination by different agencies (wind, insect)
(iii) Study of urinogenital system and circulatory system of frog. (by chart and models)
(iv) Study of the nervous system of Cockroach. (by chart and models)
Minor Experiments:
(i) Study of stages of meiosis in grasshopper testes and comment. (available permanent slide)
(ii) Study tissue section for nucleic acid (acetocarmine stain, permanent slide) and comment. (available permanent slide)
(iii) Study of homologous and analogous organs in plants and animals and comment.
(iv) Study plants and animals of aquatic conditions. Comment upon their adaptations.
(v) Study plants and animals found in dry conditions. Comment upon their adaptation.
(vi) Study of t.s. of blastula and gastrula of frog and rabbit. (available permanent slide)
Ecology :
(i) Collect and study soil from different sites and study them for moisture content.
(ii) Study the pH and water holding capacity of soil.
(iii) Study the soil biota from different sites.
Haematology and Biochemistry :
(i) Determination of Haemoglobin in blood by Haemoglobinometer.
(ii) Total count of RBC and WBC in blood b y Haemocytometer.
(iii) Study of carbohydrate, protein and fats in plant and animals tissues.
(iv) Study of Human A, B, O blood groups.
Spotting with suitable comments :
(i) One from infections and disease due to organisms like helminthes (Ascaris, filaria),
(ii) Entamoeba, One from seeds.
(iii) One from fruits.
(iv) One from stages of mitosis and meiosis (permanent slides).
Pollen showing (with pollen tube)
(v) One from reproductive organs as T.S. of testes and T.S. of ovary in mammals (permanent slide),T.S. of ovary of flower.
(vi) One from homologous and analogous organs.
Bihar Board Class 12 Biology Syllabus 2025-26: How to Download
The syllabus of biology class 12 bihar board 2026 can be downloaded from the official website as well. Follow the simple steps given below to download the syllabus:
Step 1: Open the official website of the Bihar Board, biharboardonline.bihar.gov.in.
Step 2: On the homepage, click on the ‘BSEB 12th Syllabus 2025-26’ link under the latest updates.
Step 3: Now, select the subject (Biology) and language you want to download the syllabus.
Step 4: Click to download the Bihar Board class 12 syllabus pdf.
Step 5: Download and save the BSEB 12th Biology syllabus 2025-26 for future reference.
Students are advised to complete the Bihar Board Class 12 Biology Syllabus 2025-26 a month or two before the commencement of the exam. They must keep the last two months for solving the BSEB 12th previous year question papers and model papers.
