CBSE Class 12 Biology Weightage 2026 is important for students appearing in the 2026 board exams. It shows the marks distribution across different chapters, helping students identify which topics carry higher marks such as Genetics, Biotechnology, Ecology, and Human Physiology.
Understanding the CBSE Class 12 Biology chapter wise weightage allows students to focus more effectively on key chapters, manage their study time better and increase their chances of scoring high in the exam.
Biology exam for Class 12 emphasizes conceptual clarity, diagrams and application-based questions. Below is an overview of the marks distribution.
CBSE Class 12 Biology Weightage 2026 Overview |
||
Component |
Marks |
Overview |
Theory Exam |
70 |
Includes all Biology units with emphasis on concepts, diagrams, and application based questions |
Practical Exam |
30 |
Covers experiments, record work, project and viva |
Total |
100 |
Balanced assessment of theoretical understanding and practical skills |
Biology Class 12 Chapter wise Weightage CBSE 2025-26 helps students know how marks are divided across chapters. The table below shows the chapter-wise marks distribution:
Chapter wise Weightage for CBSE Class 12 Biology |
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Unit |
Chapter |
Marks |
Unit VI: Reproduction |
Sexual Reproduction in Flowering Plants |
|
Human Reproduction |
||
Reproductive Health |
16 |
|
Unit VII: Genetics and Evolution |
Principles of Inheritance and Variation |
|
Molecular Basis of Inheritance |
||
Evolution |
20 |
|
Unit VIII: Biology and Human Welfare |
Human Health and Diseases |
|
Microbes in Human Welfare |
12 |
|
Unit IX: Biotechnology and Its Applications |
Biotechnology – Principles and Processes |
|
Biotechnology and Its Applications |
12 |
|
Unit X: Ecology and Environment |
Organisms and Populations |
|
Ecosystem |
||
Biodiversity and Its Conservation |
10 |
|
Total |
— |
70 Marks |
CBSE Weightage of Marks Class 12 Biology practical exam helps students understand how marks are distributed in different segments. Knowing the weightage makes it easier to prepare for each section effectively.
CBSE Class 12 Biology Practical Weightage 2026 |
|
Evaluation Scheme |
Marks |
One Major Experiment |
5 |
One Minor Experiment |
4 |
Slide Preparation |
5 |
Spotting |
7 |
Practical Record + Viva Voce |
4 |
Investigatory Project and its Project Record + Viva Voce |
5 |
Total |
30 |
To score well in Biology, students should first understand the Biology Class 12 Chapter wise Weightage CBSE 2025-26 and plan their preparation accordingly. Giving more time to high-weightage chapters will help in securing better marks.
Go through the complete Class 12 Biology syllabus 2026 and understand the marks distribution.
Prepare short notes of important topics for quick revision.
Practice diagrams regularly as they carry significant marks in the exam.
Solve CBSE Class 12th Previous Year Question Papers and sample papers to improve speed and accuracy.
Revise the topics multiple times, especially those with high weightage.
Follow a timetable and divide the syllabus for balanced preparation and revision.