Bihar Board Class 12 Biology Syllabus 2026 – Download BSEB 12th Bio PDF & Marks Distribution

Download Bihar Board 12th Biology Syllabus 2025-26

Students can directly click on the given link and download the BSEB 12th Biology syllabus PDF. They can prepare for the Bihar Board 12th exam.

Download BSEB 12th Biology Syllabus PDF: Click Here

Bihar Board 12th Biology Syllabus Units & Marking Scheme

Students need to answer around 35 MCQs, 10 short-answer questions, and 3 long-answer questions. The BSEB 12th biology marks units which carry the most marks are Genetics, Biotechnology, Human Welfare, and Environment. We have provided unit wise marking scheme below.

Check the other subject BSEB 12th syllabus and Bihar Board 12th exam pattern here

Detailed BSEB 12th Biology Syllabus 2025-26: Topic Wise

Students can tick the topics they have covered and complete their syllabus chapter-wise and topic-wise. They can also download the Bihar Board 12th biology syllabus PDF given above and paste it on the wall.

Unit 1: Reproduction

• Sexual Reproduction in Flowering Plants: Pollination and Fertilisation

• Development of the seed and fruit

• Reproduction in Humans: Male and Female Reproductive System, Menstrual cycle, production of gametes.

• Fertilisation, implantation, embryo development, pregnancy and parturition.

• Reproductive health: birth control, contraception and STDs.

Unit 2: Genetics and evolution

• Basics of Inheritance: Chromosome Theory

• Deviations from the Mendelism ratio

• Sex determination in Humans.

• Linkage and crossing over

• Blood groups in human beings: Inheritance pattern of haemophilia.

• DNA, replication, transcription, translation

• Gene expression and regulation, DNA Fingerprinting

• Genome and Human Genome Project

• Evolution: Theories and evidence

Unit 3: Biology & Human Welfare

• Microbes in Human Welfare: household food processing, industrial production, Sewage treatment and energy generation

• Cancer and AIDS

• Adolescence and drug and alcohol abuse

• Microbes as Biocontrol Agents Microbes as Biofertilizers

• Animal Husbandry

• Basic concepts of immunology, vaccines,

• Enhancement in Food Production Plant Breeding Tissue Culture: Concept of Cellular Totipotency, Requirements of Tissue Culture (in brief)

• Callus Culture, Suspension Culture

• Single Cell Protein. Biofortification

Unit 4: Biotechnology and its applications

• Biotechnology Process

• Recombinant DNA technology: molecular diagnostic technique.

• Applications in Health & Medicines

• Applications in Agriculture

• Genetically modified (GM) organisms, Biosafety issues

Unit 5: Ecology and environment

• Organisms and Environment

• Ecosystem

• Ecological pyramids

• Ecological Succession

• Nutrient Cycling

• Ecosystem Services

• Biodiversity and its Conservation

• Environmental Issues

Practical Experiments Asked in Bihar Board 12th Biology Exam

The board gives 12th biology experiments directly from the topics given below or similar ones. Students should prepare these BSEB 12th biology experiments thoroughly, along with the possible questions that can be asked on them.

Major Experiments:

• Study the reproducing part of different flowers.

• Study of flowers adapted to pollination by different agencies (wind, insect)

• Study of the urinogenital system and the circulatory system of the frog. (by chart and models)

• Study of the nervous system of the cockroach. (by chart and models)

Minor Experiments:

• Study of stages of meiosis in grasshopper testes and comments. (available permanent slide)

• Study tissue section for nucleic acid (acetocarmine stain, permanent slide) and comment. (available permanent slide)

• Study of homologous and analogous organs in plants and animals, and comment.

• Study plants and animals in aquatic conditions. Comment on their adaptations.

• Study plants and animals found in dry conditions. Comment on their adaptation.

• Study of the t.s. of blastula and gastrula of frog and rabbit. (available permanent slide)

Ecology

Collect and study soil from different sites and study them for moisture content.

Study the pH and water-holding capacity of soil.

Study the soil biota from different sites.

Haematology and Biochemistry :

Determination of Haemoglobin in blood by Haemoglobinometer.

Total count of RBC and WBC in blood by Haemocytometer.

Study of carbohydrates, proteins, and fats in plant and animal tissues.

Study of Human A, B, O blood groups.

Spotting with suitable comments :

One from infections and disease due to organisms like helminths (Ascaris, filaria),

Entamoeba, one from seeds.

One from fruits.

One from the stages of mitosis and meiosis (permanent slides).

Pollen showing (with pollen tube)

One from reproductive organs as T.S. of testes and T.S. of ovary in mammals (permanent slide), T.S. of the ovary of a flower.

(vi) One from homologous and analogous organs.

Bihar Board 12th Biology Experiments Marking Scheme