CBSE Class 12 Biology — Guess Paper & Important Questions 2027
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Everything for Biology in one place — guess paper, important questions and chapter-wise important topics for the 2027 exam, from analysis of 5 board + 2 official sample papers (2022–2026).
Guess Paper 2027
A full 33-question paper on the official pattern, built from the most-likely questions.
Open guess paper PDFImportant Questions
53 question patterns that have repeated across past papers.
See repeated questions PDFImportant Topics
Every chapter’s topics ranked by how often and how recently they were asked.
See important topicsTop 5 topics
| # | Topic | Chapter | Importance |
|---|---|---|---|
| 1 | Tools of recombinant DNA technology (restriction enzymes, vectors, host organism) | Biotechnology - Principles and Processes | ★★★★★ |
| 2 | Processes of recombinant DNA technology (steps of gene cloning) | Biotechnology - Principles and Processes | ★★★★☆ |
| 3 | Immunity: innate and acquired; vaccination and immunisation | Human Health and Disease | ★★★★☆ |
| 4 | DNA structure and the search for genetic material (Griffith, Hershey-Chase) | Molecular Basis of Inheritance | ★★★★☆ |
| 5 | Structure of flower; microsporogenesis and structure of pollen grain | Sexual Reproduction in Flowering Plants | ★★★☆☆ |
CBSE Class 12 Biology exam pattern 2027
Key facts
- Maximum marks: 70
- Duration: 3 hours
- Sections: 5 (A, B, C, D, E)
- Exam: 2027 CBSE Class 12 board exam
| Section | What is asked | Marks |
|---|---|---|
| A | 16 questions of 1 mark each — 12 MCQ + 4 Assertion-Reason | 16 |
| B | 5 Very Short Answer questions of 2 marks each | 10 |
| C | 7 Short Answer questions of 3 marks each | 21 |
| D | 2 Case-based questions of 4 marks each (with sub-parts) | 8 |
| E | 3 Long Answer questions of 5 marks each | 15 |
CBSE Class 12 Biology chapter-wise weightage 2027
| Unit | Chapters | Marks |
|---|---|---|
| Reproduction | Sexual Reproduction in Flowering Plants, Human Reproduction, Reproductive Health | 16 |
| Genetics and Evolution | Principles of Inheritance and Variation, Molecular Basis of Inheritance, Evolution | 20 |
| Biology and Human Welfare | Human Health and Disease, Microbes in Human Welfare | 12 |
| Biotechnology and its Applications | Biotechnology - Principles and Processes, Biotechnology and its Applications | 12 |
| Ecology and Environment | Organisms and Populations, Ecosystem, Biodiversity and Conservation | 10 |
Unit marks as given in the official syllabus.
Frequently asked questions
Is this the real CBSE Class 12 Biology guess paper 2027?
No. It is a practice guess paper built by analysing which questions and topics repeat across 5 board + 2 official sample papers (2022–2026) for CBSE Class 12 Biology. It follows the latest official exam pattern but is not an official or leaked paper.
What is the CBSE Class 12 Biology exam pattern for 2027?
The CBSE Class 12 Biology 2027 paper is 70 marks and 3 hours long, in 5 sections: Section A — 16 questions of 1 mark each — 12 MCQ + 4 Assertion-Reason; Section B — 5 Very Short Answer questions of 2 marks each; Section C — 7 Short Answer questions of 3 marks each; Section D — 2 Case-based questions of 4 marks each (with sub-parts); Section E — 3 Long Answer questions of 5 marks each. Highest-weightage units: Genetics and Evolution (20 marks), Reproduction (16 marks), Biology and Human Welfare (12 marks).
How many questions repeat in CBSE Class 12 Biology?
We found 53 question patterns that appeared in two or more of the analysed papers (5 board + 2 official sample papers). The most-repeated ones are listed on the Important Questions page.
What are the most important topics for CBSE Class 12 Biology 2027?
The top topics by repetition are Tools of recombinant DNA technology (restriction enzymes, vectors, host organism); Processes of recombinant DNA technology (steps of gene cloning); Immunity: innate and acquired; vaccination and immunisation. The full ranked list is on the Important Topics page.
Where can I see the CBSE Class 12 Biology guess paper?
The full 33-question guess paper is on the Guess Paper page — free to view, with each question tagged by chapter and how often it has appeared in past papers.