The CBSE Class 12 Biology (044) marking scheme for 2026-27 carries 100 marks in total, with a 70-mark theory paper of 3 hours and 30 marks for practicals.  

  • Theory paper: The paper has 33 questions in five sections (A to E), with no overall choice but internal choice in some questions.
  • Highest weightage: Genetics and Evolution carries 20 marks, which is about 29% of the paper, followed by Reproduction with 16 marks.
  • Practical exam: The 30 marks include a major experiment (5), minor experiment (4), spotting (7) and practical record with viva (4), along with slide preparation and project work.
  • Pattern: CBSE has mentioned that there is no change in the question paper design and assessment pattern for 2026-27.

As per the CBSE Class 12 Marking Scheme 2026, students must score a minimum of 33% aggregate marks to pass the board examination. In addition, it is mandatory to secure at least 33% marks in each subject separately.

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CBSE Biology marking Scheme

Key Summary

  • The scheme below is based on the official 2026-27 sample question paper and the syllabus released by CBSE for the Class 12 Board Exam 2027.
  • The theory paper is divided into five units worth 70 marks, and CBSE has not given chapter-wise weightage.
  • The final board paper may differ in questions, but the section-wise structure is expected to follow the sample paper.
  • The sample paper uses data-based, case-based and diagram-based questions, so interpretation skills matter along with NCERT facts.

CBSE Class 12 Biology 2026-27: Theory Paper Marking Scheme

The theory paper of 70 marks has 33 questions, and Section C carries the highest marks (21 marks).

  • Section A has 12 MCQs (Q1 to Q12) and 4 Assertion-Reason questions (Q13 to Q16) of 1 mark each.
  • Section D has 2 case-based questions of 4 marks each, and Section E has 3 long answer questions of 5 marks each.
  • Students should draw neat and properly labelled diagrams wherever necessary.
Section Question Type No. of Questions Marks per Question Total Marks
A MCQs (12) and Assertion-Reason (4) 16 1 16
B Very Short Answer 5 2 10
C Short Answer 7 3 21
D Case Based 2 4 8
E Long Answer 3 5 15
Total 33 70

Ques. How many marks is the CBSE Class 12 Biology theory paper?

Ans. The theory paper is of 70 marks with a duration of 3 hours. The remaining 30 marks are for practicals, making the total 100 marks.

Ques. Is there internal choice in the CBSE Class 12 Biology paper?

Ans. Yes, internal choices are given in some questions, and students must attempt only one of the alternatives. There is no overall choice, so all 33 questions must be answered.

CBSE Class 12 Biology 2026-27: Unit-Wise Marks Distribution

Genetics and Evolution carries the maximum 20 marks, and the top two units together carry 36 marks, which is over half of the paper.

  • Biology and Human Welfare and Biotechnology and its Applications carry 12 marks each.
  • Ecology and Environment carries 10 marks.
Unit Unit Name Chapters Included 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

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Ques. Which unit has the highest weightage in CBSE Class 12 Biology?

Ans. Genetics and Evolution has the highest weightage of 20 marks. Reproduction is the second highest with 16 marks.

How Marks Are Split in the CBSE Class 12 Biology Paper

The official sample paper shows the marks given to each part of a question, and many answers in Sections C, D and E are divided into sub-parts.

Question Marks Split of Marks (Official Sample Paper)
Section A (Q1 to Q16) 1 Full mark for the correct option
Section C (for example Q24, genetics cross) 3 Three parts of 1 + 1 + 1 marks
Section D (Q29, case based) 4 Sub-parts of 1 + 2 + 1 marks
Section E (Q32, option A) 5 Parts of 2 + 2 + 1 marks
Section E (Q33, option A) 5 Parts of 4 + 1 marks
  • Diagrams: Labelled diagrams, tables and Punnett squares should be drawn wherever the question asks for them.
  • Data questions: Several Section B and C questions give a data table and ask for interpretation, so answers should refer to the data.

CBSE Class 12 Biology Practical Marking Scheme (30 Marks)

The practical exam is of 30 marks, and spotting carries the highest single component (7 marks).

Component Marks
One Major Experiment 5
One Minor Experiment 4
Spotting 7
Practical Record and Viva Voce 4
Slide Preparation and Investigatory Project (with viva) 10
Total 30

CBSE Class 12 Biology Marking Scheme Official PDFs: Last 3 Years

Students can download the official CBSE Class 12 Biology marking scheme from the links below:

Session Document Download Link
2026-27 CBSE Class 12 Biology Marking Scheme 2026-27 Download PDF | Official Page
2025-26 CBSE Class 12 Biology Marking Scheme 2025-26 Download PDF | Official Page
2024-25 CBSE Class 12 Biology Marking Scheme 2024-25 Download PDF | Official Page
Note: PDFs are published by the Central Board of Secondary Education (CBSE). Links are updated as official documents are released.

FAQs

Ques. Where can I download the CBSE Class 12 Biology marking scheme 2026-27?

Ans. The marking scheme is available on cbseacademic.nic.in under the Class XII Sample Question Paper and Marking Scheme section for 2026-27. The direct PDF link is given in the table above.

Ques. What is the passing criteria for CBSE Class 12 Biology?

Ans. Students need a minimum of 33% in the subject, and 33% separately in theory and practical. Check the latest CBSE passing criteria notice for exact figures.

Ques. Does CBSE release an official answer key for Biology after the board exam?

Ans. CBSE does not generally release an official answer key right after the exam. Students can use the official sample paper marking scheme to understand how answers are evaluated.