# CBSE Class 12 Biology Syllabus 2026-27, Unit Marks | SwaVid

CBSE Class 12 Biology syllabus 2026-27: 70 marks theory, 3 hours and 30 marks practical. Official marks, unit by unit, with the source page linked.

Canonical: https://www.swavid.com/cbse/class-12/biology/syllabus

Source: https://www.swavid.com/cbse/class-12/biology/syllabus

# Class 12 Biology Syllabus 2026-27

## Unit-wise marks

## Practical: 30 marks

## NCERT textbook chapters

## Practise this syllabus

## Questions parents ask

## Find the earlier idea your child is missing

### Biology (Class XII)

### Sample paper 2026-27

### Class 12 Biology

CBSE’s official unit marks, the chapters in each unit and the paper design.

CBSE prints marks for units, not for individual chapters.

Theory is 70 marks. CBSE prints marks for each unit, not for each chapter.

Source : CBSE Curriculum 2026-27, Biology (044) Class XI-XII , p.9

CBSE does not publish marks for individual chapters. A claim such as “one chapter carries 6 marks” is not from CBSE. Use the unit marks.

Short answer. The Class 12 Biology theory paper is 70 marks and 3 hours. The practical is 30 marks. The marks are split over 5 units: Reproduction 16, Genetics and Evolution 20, Biology and Human Welfare 12, Biotechnology and its Applications 12 and Ecology and Environment 10.

Source : CBSE Curriculum 2026-27, Biology (044) Class XI-XII , p.9

Checked against the official CBSE pages on 3 November 2026. 2026-27 is the latest curriculum CBSE has published.

The practical exam is 3 hours.

Source : CBSE Curriculum 2026-27, Biology (044) Class XI-XII , p.12

The chapter lists printed in the NCERT books (Reprint 2026-27). Match topics to the CBSE units above by name.

Source : NCERT textbook page: Biology (Class XII) , contents

The official sample paper and marking scheme from CBSE.

Syllabus, sample paper and past papers for this subject on one page.

The theory paper is 70 marks and 3 hours. The practical is 30 marks.

Genetics and Evolution carries the most, 20 of the 70 marks.

No. CBSE publishes marks per unit only. Chapter-wise weightage tables on other sites are not from CBSE.

Yes. CBSE released the 2026-27 sample question papers and marking schemes on 21 September 2026. The sample paper page for this subject links the official files.

SwaVid finds the earlier idea a student is missing, repairs it, then teaches the topic step by step.

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- SwaVid
- CBSE
- Class 12
- Biology
- Syllabus 2026-27
- 70 marks theory
- 3 h board paper
- 30 practical
- Unit VI: 1 Sexual Reproduction in Flowering Plants
- 2 Human Reproduction
- 3 Reproductive Health
- Unit VII: 4 Principles of Inheritance and Variation
- 5 Molecular Basis of Inheritance
- 6 Evolution
- Unit VIII: 7 Human Health and Disease
- 8 Microbes in Human Welfare
- Unit IX: 9 Biotechnology: Principles and Processes
- 10 Biotechnology and its Applications
- Unit X: 11 Organisms and Populations
- 12 Ecosystem
- 13 Biodiversity and Conservation

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- [Open the official PDF](https://cbseacademic.nic.in/web_material/CurriculumMain27/SecPart2/Biology_SecP2_2026-27.pdf)
- [CBSE Curriculum 2026-27, Biology (044) Class XI-XII](https://cbseacademic.nic.in/web_material/CurriculumMain27/SecPart2/Biology_SecP2_2026-27.pdf)
- [CBSE Curriculum 2026-27, Biology (044) Class XI-XII](https://cbseacademic.nic.in/web_material/CurriculumMain27/SecPart2/Biology_SecP2_2026-27.pdf)
- [CBSE Curriculum 2026-27, Biology (044) Class XI-XII](https://cbseacademic.nic.in/web_material/CurriculumMain27/SecPart2/Biology_SecP2_2026-27.pdf)
- [NCERT textbook page: Biology (Class XII)](https://ncert.nic.in/textbook.php?lebo1=0-13)
- [Open the sample paper page](https://www.swavid.com/cbse/class-12/biology/sample-paper-2026-27)
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