As the board exam is just a day away, so the Class 12 Biology Marking Scheme becomes extremely important. Since the paper follows an apparent blueprint, students get a fair idea of the number of questions, the marking distribution, and the chapter-wise weightage. Students preparing for multiple subjects can also refer to the CBSE Class 12 marking scheme to understand how different subjects are evaluated under the CBSE pattern.
What is the CBSE Class 12 Biology Exam Pattern and Marking Scheme 2025
The Class 12 Biology Marking Scheme includes the complete structure of the theory paper, practical evaluation, and competency-based distribution. Since the exam is just around the corner, knowing how each question type contributes to the final score helps students plan their revision effectively.
Unit-Wise Weightage for CBSE Class 12 Biology 2025
There are five major units in the Biology syllabus,so the Class 12 Biology Marking Scheme allocates different marks to each unit. Therefore, students should invest their revision time according to the marks assigned.
| Unit | Title | Marks |
| VI | Reproduction | 16 |
| VII | Genetics and Evolution | 20 |
| VIII | Biology and Human Welfare | 12 |
| IX | Biotechnology and its Applications | 12 |
| X | Ecology and Environment | 10 |
| Total | 70 |
Hence, students can visit the official syllabus page to view the theory, practical, and list of experiments in detail.
How is the CBSE Class 12 Biology Question Paper Design 2025
Here is an explanatory section of the Class 12 Biology Marking Scheme which will clearly explain how the total marks are distributed across competencies.
| Competency | Description | Weightage) | Marks (out of 70) | Question Types Included |
| Demonstrate Knowledge and Understanding | Assessing students’ ability to recall, comprehend, and explain fundamental concepts, definitions, and facts. | 50% | 35 | Objective-type questions, Very Short Answer, Short Answer |
| Application of Knowledge/Concepts | Evaluates the application of biology concepts and theories in real-life scenarios, experiments, and case studies. | 30% | 21 | Case-based questions, Application-based Short Answer |
| Analyse, Evaluate, and Create | Tests analytical skills, critical evaluation, data interpretation, and creative thinking in biological contexts. | 20% | 14 | Case-based questions, Long Answer, Analysis-based Short Answer |
Moreover, this structure encourages a balanced approach, combining strong conceptual learning with higher-order thinking.
CBSE Class 12 Biology Exam Pattern 2025: Section-Wise Breakdown
The Class 12 Biology Marking Scheme includes five sections. Here is the complete pattern:
| Section | Number of Questions | Marks per Question | Total Marks | Question Type |
| Section A | 16 | 1 | 16 | Short answer questions |
| Section B | 5 | 2 | 10 | Short answer questions |
| Section C | 7 | 3 | 21 | Medium answer questions |
| Section D | 2 | 4 | 8 | Case-based questions |
| Section E | 3 | 5 | 15 | Long answer questions |
Additional Rules:
- First, all of the questions are compulsory
- Secondly, there is no overall choice
- Students will see the internal choice in some questions
- Moreover, students are required to make neat diagrams wherever needed.
Hence, this simplified view of the Class 12 Biology Marking Scheme helps students prepare strategically for each section.
CBSE Class 12 Biology Chapter-Wise Weightage 2025-26 (Theory)
Since every chapter carries a different score distribution,it is important to know the exact marks, which will help students to revise with purpose. Here is the detailed chapter-wise list as per the updated Class 12 Biology Marking Scheme:
| Unit | Chapter | Weightage |
| Unit VI: Reproduction | Sexual Reproduction in Flowering Plants | 7 marks |
| Human Reproduction | 6 marks | |
| Reproductive Health | 3 marks | |
| Total | 16 marks | |
| Unit VII: Genetics and Evolution | Principles of Inheritance and Variation | 8 marks |
| Molecular Basis of Inheritance | 8 marks | |
| Evolution | 4 marks | |
| Total | 20 marks | |
| Unit VIII: Biology and Human Welfare | Human Health and Diseases | 9 marks |
| Microbes in Human Welfare | 3 marks | |
| Total | 12 marks | |
| Unit IX: Biotechnology and Its Applications | Biotechnology – Principles and Processes | 6 marks |
| Biotechnology and Its Applications | 6 marks | |
| Total | 12 marks | |
| Unit X: Ecology and Environment | Organisms and Populations | 5 marks |
| Ecosystem | 3 marks | |
| Biodiversity and Its Conservation | 2 marks | |
| Total | 10 marks |
These categories highlight why students must give more attention to high-weight chapters like Genetics, Evolution, and Reproduction.
CBSE Class 12 Biology Practical Exam Weightage 2026
The Class 12 Biology Marking Scheme for practicals includes:
| Evaluation Component | Marks |
| One Major Experiment | 5 |
| One Minor Experiment | 4 |
| Slide Preparation | 5 |
| Spotting | 7 |
| Practical Record + Viva | 4 |
| Investigatory Project + Viva | 5 |
| Total | 30 Marks |
Hence, students must prepare experiments,, and record carefully, as practicals contribute significantly to the final score.
Important Chapters to Focus for the 2026 Biology Board Exam
Since the Class 12 Biology Marking Scheme highlights specific scoring topics, here are the most important chapters:
- Molecular Basis of Inheritance
- Principles of Inheritance and Variation
- Human Reproduction
- Reproductive Health
- Human Health and Diseases
- Biotechnology: Principles and Processes
- Ecosystem and Biodiversity
These chapters appear regularly and carry high marks.
Steps to Download the CBSE Class 12 Biology Exam Pattern and Marking Scheme
To directly download the official Class 12 Biology Marking Scheme, follow these steps:
- First, visit the official CBSE website.
- Then, click on Sample Question Paper on the home page.
- Choose SQP 2024-25 from the dropdown.
- Select Class XII.
- Click MS next to Biology to download the official marking scheme PDF.
- Click SQP to view the sample question paper.
Hence, following these steps will allow students to check the latest format and revise according to the official pattern. Similarly, students appearing for other science subjects can also check the CBSE Class 12 Physics marking scheme 2025 to plan their Physics preparation according to unit-wise weightage and exam blueprint.
BSE Class 12 Biology Preparation Tips 2026
Since the exam demands conceptual knowledge and diagram accuracy, use the Class 12 Biology Marking Scheme to guide your final revision.
1. Understand the Syllabus and Pattern
Firstly, try to understand the structure as it helps you divide your study time wisely. Along with Biology, students should also align their revision strategy for Chemistry by referring to the Class 12 Chemistry marking scheme to understand unit-wise importance and question patterns.
2. Focus on High-Weightage Chapters
Secondly, give priority to Genetics, Evolution, Reproduction, and Biotechnology.
3. Master Diagrams
Moreover, use clear, labelled diagrams, which will help to score full marks effortlessly.
4. Revise NCERT Thoroughly
Most questions come directly or indirectly from NCERT, so revise it thoroughly.
5. Solve Sample Papers
Solve PYQs and sample papers as it will T help to improve speed and question interpretation.
6. Build Conceptual Understanding
Moreover, avoid memorizing blindly, try to understand the logic behind each process.
7. Prepare Practical Components
Lastly, follow proper slide preparation, spotting practice, and experimental steps.
Conclusion
The Class 12 Biology Marking Scheme clearly explains how the board evaluates every section of the exam, and therefore it gives students a direct path to prepare with confidence. As the paper follows a structured pattern with defined weightage for every unit, students gain a clear understanding of which chapters demand more attention and which areas can be revised quickly. Moreover, since the Class 12 Biology Marking Scheme highlights the importance of both theory and practical components, students can strengthen their preparation by balancing conceptual clarity with hands-on skills. Additionally, when the blueprint is understood well, students manage their time better, attempt every question With the right strategy, NCERT-focused study, regular practice of PYQs and sample papers, and support from reliable academic resources from SPM & LALANS COACHING, students can confidently aim for top scores in Biology.
FAQs
1. What is the chapter-wise weightage in the Class 12 Biology Marking Scheme 2025-26?
It includes five major units, with Genetics (20 marks) and Reproduction (16 marks) carrying the highest weightage.
2. Which chapter carries the highest marks in Biology?
Genetics and Evolution carries the highest marks as per the Class 12 Biology Marking Scheme.
3. How many marks are allotted for Biology practicals?
The practical exam carries 30 marks.
4. What is the weightage of Genetics and Reproduction?
Genetics: 20 marks
Reproduction: 16 marks
