CBSE Class 12 Biology Syllabus 2025-26 (PDF, Units, Marks, Practicals)

The Central Board of Secondary Education (CBSE) has released the Class 12 Biology syllabus for the academic session 2025-26. This syllabus provides students with detailed unit-wise chapters, marks distribution, and practical guidelines to help them prepare for the CBSE board exam effectively.

Download CBSE Class 12 Biology Syllabus PDF 2025-26

Students can download the official CBSE 12th Biology Syllabus PDF from the CBSE academic portal:

CBSE Class 12 Biology Syllabus 2025-26: Unit-Wise Breakdown

Unit I: Reproduction – 16 Marks

  • Chapter 1: Sexual Reproduction in Flowering Plants
    Pollination, double fertilization, fruit formation, apomixis, parthenocarpy.
  • Chapter 2: Human Reproduction
    Male & female reproductive systems, gametogenesis, menstrual cycle, pregnancy, lactation.
  • Chapter 3: Reproductive Health
    Birth control, STD prevention, infertility treatments (IVF, ZIFT, GIFT).

Unit II: Genetics and Evolution – 20 Marks

  • Chapter 4: Principles of Inheritance and Variation
    Mendelian inheritance, sex determination, disorders like thalassemia, Down’s syndrome.
  • Chapter 5: Molecular Basis of Inheritance
    DNA, RNA, replication, transcription, translation, Human Genome Project.
  • Chapter 6: Evolution
    Darwin’s theory, natural selection, Hardy-Weinberg principle, human evolution.

Unit III: Biology and Human Welfare – 12 Marks

  • Chapter 7: Human Health and Disease
    Diseases (malaria, dengue, AIDS), vaccination, drug abuse.
  • Chapter 8: Microbes in Human Welfare
    Use of microbes in industries, antibiotics, biocontrol agents.

Unit IV: Biotechnology and Its Applications – 12 Marks

  • Chapter 9: Biotechnology: Principles and Processes
    Recombinant DNA technology.
  • Chapter 10: Biotechnology and Its Applications
    GM crops, stem cell therapy, gene therapy, biopiracy, biosafety.

Unit V: Ecology and Environment – 10 Marks

  • Chapter 11: Organisms and Populations
    Population dynamics, mutualism, predation.
  • Chapter 12: Ecosystem
    Energy flow, ecological pyramids, productivity.
  • Chapter 13: Biodiversity and Its Conservation
    Biodiversity, extinction, Red Data Book, Ramsar sites.

CBSE Class 12 Biology Marks Distribution 2025-26

UnitTitleMarks
IReproduction16
IIGenetics and Evolution20
IIIBiology and Human Welfare12
IVBiotechnology and Applications12
VEcology and Environment10
Theory Total70
Practicals30
Grand Total100

CBSE Class 12 Biology Practical Exam Evaluation Scheme 2025-26 (30 Marks)

ComponentMarks
One Major Experiment5
One Minor Experiment4
Slide Preparation5
Spotting (at least 7)7
Practical Record + Viva Voce4
Investigatory Project + Viva5
Total30

List of Practical Activities

  • Study of flower adaptations for pollination.
  • Identification of morula/blastula (model only).
  • Simulating Mendelian inheritance using colored seeds/beads.
  • Preparing pedigree charts (e.g., tongue rolling, color blindness).
  • Practicing emasculation, tagging, and bagging (controlled pollination).

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