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    CBSE 12th Class Biology Answer Key 2026 PDF (25 March)

    CBSE 12th Class Biology Answer Key 2026 PDF (25 March)

    Garima SihagUpdated on 26 Mar 2026, 05:35 PM IST

    The CBSE Class 12 Biology exam for the 2025-26 session will be held on March 27, 2026. The paper will be conducted from 10:30 AM to 1:30 PM. After the exam, the different coaching institutes will release the CBSE 12th Biology answer key online. These Class 12 Biology answer keys sessions will run on different YouTube channels and websites. Students will be able to check those CBSE Class 12 Biology answers from this page as well.

    Live | Mar 26, 2026 | 6:00 PM IST

    This Story also Contains

    1. Download CBSE 12th Biology Answer Key 2026
    2. How can I calculate the score using the answer key?
    3. CBSE 12th Exam Pattern 2026 & Marking Scheme
    4. CBSE 12th Biology 2026 High Priority Chapters

    Download CBSE 12th Biology Answer Key 2026

    The CBSE Class 12 Biology exam includes a variety of question types such as Multiple Choice Questions (MCQs), short answer questions, long answer questions, case-based or competency-based questions, and diagram-based questions. We will provide the answers to these CBSE 12th questions on this page.

    How can I calculate the score using the answer key?

    To estimate the marks, follow the CBSE 12th marking structure:

    • Section A (MCQs): 1 mark for each correct option. There is no negative marking.

    • Step Marking: For Sections B, C, and E, CBSE provides step-wise marks. Even if the final answer is wrong, students can get marks for correct formulas, intermediate steps, or labelled diagrams.

    • Diagrams: In Biology, a correctly drawn but unlabeled diagram fetches lower marks. Ensure the labels match the NCERT standard.

    CBSE 12th Exam Pattern 2026 & Marking Scheme

    The CBSE Class 12 paper carries 70 marks, with the remaining 30 marks coming from the practical examination. The question paper is divided into five sections:

    • Section A: 16 questions (MCQs and Assertion-Reason): 1 mark each.

    • Section B: 5 very short answer questions: 2 marks each.

    • Section C: 7 short answer questions: 3 marks each.

    • Section D: 2 case-based questions: 4 marks each.

    • Section E: 3 long answer questions: 5 marks each.

    CBSE Class 12 Biology: Unit-Wise Weightage

    Unit No.Unit NameWeightage (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

    CBSE 12th Biology 2026 High Priority Chapters

    Focusing on these chapters will help to secure maximum marks as they often contain high-weightage derivations and diagrams:

    1. Molecular basis of inheritance: Heavy focus on DNA replication, transcription, and translation processes.

    2. Genetics (Principles of Inheritance): Mastering Mendelian crosses and pedigree analysis is essential.

    3. Human Reproduction: Requires precise diagrams of the reproductive systems and a clear understanding of the menstrual cycle.

    4. Biotechnology - Principles and Processes: Understanding recombinant DNA technology and PCR.

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    CBSE Class 12th Syllabus: Subjects & Chapters
    Select your preferred subject to view the chapters

    Frequently Asked Questions (FAQs)

    Q: When will the Biology answer key be available?
    A:

    CBSE Class 12 Biology answer key will not release the official answer key. However, many subject experts and coaching teachers upload their solutions soon after the board exam ends.

    Q: Can I challenge the answer key or apply for re-evaluation?
    A:

    Yes, after the CBSE results are announced in May, the board provides a window for:

    1. Verification of Marks: A simple re-totalling of the score.

    2. Obtaining a Photocopy: Students can request a digital copy of their evaluated answer sheet.

    3. Re-evaluation: Students can challenge specific answers if they believe they were marked incorrectly in accordance with the official marking scheme.

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