CBSE Class 12 Biology Sample Paper 2027 with Solutions, Download Model Paper PDF FREE
CBSE Class 12 Biology Sample Paper 2027 with solutions: Download the Biology model question paper PDF, marking scheme, exam pattern, preparation tips and important resources here.
CBSE Class 12 Biology Sample Paper 2027: The Central Board of Secondary Education (CBSE) has released the official sample question papers and marking schemes for the Class 12 board examinations. Students preparing for the CBSE Class 12 Biology Board Exam 2027 can use the Biology sample paper to understand the latest question paper pattern, marking scheme, question types and difficulty level expected in the examination.
The CBSE Class 12 Biology Sample Paper 2027 PDF is an important resource for students appearing for the board exams. Solving the model paper under exam-like conditions can help students assess their preparation, identify weak areas and improve their time-management skills.
CBSE Class 12 Biology Sample Paper 2027: Highlights
| Particulars | Details |
| Board | Central Board of Secondary Education |
| Class | Class 12 |
| Subject | Biology |
| Academic Session | 2026-27 |
| Exam | CBSE Class 12 Board Exam 2027 |
| Sample Paper | Biology Sample Question Paper 2027 |
| Format | |
| Marking Scheme | Available |
| Official Website | cbseacademic.nic.in |
Also Check: CBSE Class 12 Biology Syllabus 2026-27, Download PDF
CBSE Class 12 Biology Sample Paper 2027 PDF Download
General Instructions:
(i) All questions are compulsory.
(ii) The question paper has five sections and 33 questions.
(iii) Section–A has 16 questions of 1 mark each; Section–B has 5 questions of 2
marks each; Section– C has 7 questions of 3 marks each; Section– D has 2
case-based questions of 4 marks each; and Section–E has 3 questions of 5
marks each.
(iv) There is no overall choice. Answer all 33 questions. However, internal choices
have been provided in some questions. A student has to attempt only one of the
alternatives in such questions.
(v) Wherever necessary, neat and properly labeled diagrams should be drawn.
| Section – A Q. Nos. 1 to 12 are multiple choice questions. Only one of the choices is correct. Select and write the correct choice as well as the answer to these questions. | ||
| Q.NO. | QUESTION | MARKS |
| 1 | A researcher observes that in a particular flowering plant, the pistil matures several days before the stamens in all flowers of the plant. What is the most significant consequence of this timing difference? A. It guarantees self-pollination B. It promotes autogamy C. It ensures cross-pollination D. It leads to geitonogamy | 1 |
| 2 | A male patient undergoes a medical procedure where a small section of the vas deferens is cut and tied at both ends. Which of the following effects is the intended and direct result of this procedure? A. Blockage of sperm transport into the ejaculatory duct and urethra. B. Inhibition of testosterone production by the testes. C. Suppression of the formation of seminal plasma by accessory glands. D. Prevention of spermatogenesis in the seminiferous tubules. | 1 |
| 3 | During the early stage of human embryonic development, the blastomeres are arranged into an outer layer and an inner group of cells known as the Inner Cell Mass (ICM). What is the fundamental significance of the outer layer, the trophoblast? A. It is responsible for forming the primary germ layers (ectoderm, mesoderm, endoderm). B. It provides essential nutrients to developing embryo and helps in its implantation. C. It secretes colostrum which contains antibodies. D. It gives rise to all the organs of the future embryo (organogenesis). | 1 |
| 4 | Select the option that gives the correct description of the process of natural selection with respect to the length of the neck of the giraffe.
A. Stabilising selection as giraffes with longer neck lengths are selected further. B. Disruptive selection as giraffes with smaller and longer neck lengths are selected. C. Directional selection as giraffes with longer neck lengths are selected. D. Stabilising selection as giraffes with medium neck lengths are selected. | 1 |
| 5 | The initiation step during the process of transcription in bacteria is shown below. Identify A, B, C and D by selecting the option:
A. A-RNA polymerase, B-Promoter, C-Sigma factor, D-DNA helix B. A-Promoter, B-Sigma factor, C-RNA polymerase, D-DNA helix C. A-Promoter, B-RNA polymerase, C-DNA helix, D-Sigma factor D. A-Promoter, B-RNA polymerase, C-Sigma factor, D-DNA helix | 1 |
| 6 | Given below is the illustration of the different steps of experiments conducted by MacLeod, McCarty and Avery to find the chemical nature of the 'transforming principle' as DNA. Select the option that incorrectly depicts the step of the experiment.
| 1 |
| 7 | A scientist was culturing E.coli in a 15NH4Cl medium initially, then he shifted E.coli to a 14NH4Cl medium. The DNA was extracted from E.coli after 60 minutes of transfer to 14NH4Cl Medium and performed density gradient centrifugation to check the isotope distribution in newly replicated DNA. What will be the densities of DNA molecules formed? A. 25% hybrid and 75% light B. 50% hybrid and 50% light C. 75% hybrid and 25% light D. 85% hybrid and 15% light | 1 |
| 8 | Study the given pedigree and identify the disease represented
A. Myotonic Dystrophy B. Sickle cell anaemia C. Haemophilia D. Colour blindness | 1 |
| 9 | A patient with fever, chest pain, cough and breathing difficulty undergoes a chest X-ray. The film shows patchy opacities and reduced clarity of lung fields. Which observation best supports pneumonia? A. Enlarged heart size B. Inflammation or fluid buildup in the lungs C. Fractured ribs D. Air pockets in the lungs | 1 |
| 10 | A stretch of an euchromatin has 200 nucleosomes, how many base pairs (bp) will be there in the stretch and what would be the length of the typical euchromatin? A. 20,000 bp and 13,000x10-9 m B. 10,000 bp and 10,000x10-9 m C. 40,000 bp and 13,600x10-9 m D. 40,000 bp and 13,900x10-9 m | 1 |
| 11 | A biotechnology company grew Streptomyces in a fermenter to produce an antibiotic. It was observed that Day 7 onwards, the actual yield drops sharply, even though nutrient level, temperature, and aeration remain unchanged. Also, Microscopy revealed new colonies of bacteria which were not present in the original culture. So the fermenter was stopped. What measures should be taken to prevent the fall in yield in future fermentations? A. Increasing temperature only at the end of fermentation to kill contaminants. B. Adding antibiotics to the culture so unwanted microbes cannot grow. C. Ensuring sterile handling, sterilised equipment, and aseptic transfer before and during fermentation. D. Using a genetically modified strain designed to grow faster than contaminants. | 1 |
| 12 | A rice farmer's field, which typically thrives in waterlogged conditions and requires soil rich in nutrients like phosphorus, is experiencing a severe drought this year. The crop is also susceptible to root infestation by pathogens. Which of the following techniques is best to address all these issues? A. Adding nitrogen-fixing bacteria to the soil B. Applying chemical fertilizers C. Adding spores of Glomus to the soil D. Flooding the field artificially to mimic normal conditions | 1 |
| Question No. 13 to 16 consist of two statements – Assertion (A) and Reason (R). Answer these questions selecting the appropriate option given below: A. Both A and R are true and R is the correct explanation of A. B. Both A and R are true but R is not the correct explanation of A. C. A is true but R is false. D. A is False but R is true. | ||
| 13 | Assertion (A): Spermatogenesis is an ongoing process throughout the reproductive life of a human male, while oogenesis is a discontinuous process. Reason (R): Oogenesis begins during the embryonic stage, gets arrested at prophase-I, resumes after puberty, and is arrested again at metaphase-II. | 1 |
| 14 | Assertion (A): There is no variation in the percentage recombination due to loosely or tightly linked genes. Reason (R): Linked genes result in occurrence of higher proportion of parental gene combinations. | 1 |
| 15 | Assertion (A): The primary goal of sewage treatment is to eliminate all organic matter from the effluent. Reason (R): High BOD indicates a low level of organic matter in the water, which can lead to increased oxygen consumption by microorganisms, potentially harming aquatic life. | 1 |
| 16 | Assertion (A): Tissue culture is used when traditional breeding technique is insufficient to keep pace with the demand of crop improvement. Reason (R): Totipotency is the ability of a single plant cell or explant to regenerate into a whole plant under sterile conditions in nutrient media. | 1 |
CBSE has uploaded the subject-wise sample question papers and marking schemes for Class 12 on its academic portal. Students can access the Biology sample paper and its corresponding marking scheme through the official links below.
Document | Download Link |
| CBSE Class 12 Biology Sample Paper 2027 | |
| CBSE Class 12 Biology Marking Scheme 2027 | |
| CBSE Class 12 Sample Papers 2026-27 |
CBSE Class 12 Biology Sample Paper 2027 with Solutions
The CBSE Class 12 Biology Sample Paper 2027 with solutions can help students understand the correct approach to answering different types of questions. After attempting the paper, students should compare their responses with the marking scheme rather than simply checking whether their final answer is correct.
For Biology, students should pay attention to important terms, diagrams, biological processes and explanations while writing answers. Practising with the marking scheme can also help students understand how to structure answers according to the marks allotted to each question.
Class 12 Biology CBSE: Subject-wise Marks Distribution
Students should check the below table to know the Subject Wise marks distribution of CBSE 2026-27 academic year subject Biology Class 12:
| Sl. No. | Subject | Marks |
| 1. | Reproduction | 16 |
| 2. | Genetics and Evolution | 20 |
| 3. | Biology and Human Welfare | 12 |
| 4. | Biotechnology and its Applications | 12 |
| 5. | Ecology and Environment | 10 |
| Total |
| 70 |
Why Solve CBSE Class 12 Biology Sample Paper 2027?
Solving the sample paper before the board examination can benefit students in several ways:
- Understand the exam pattern: Students can familiarise themselves with the structure of the Biology question paper.
- Practise different question types: Sample papers provide practice for various formats and difficulty levels.
- Improve time management: Attempting the complete paper within the prescribed duration helps students manage exam time.
- Identify weak topics: Students can analyse their performance and revise chapters where they lose marks.
- Improve answer writing: Regular practice helps students write concise and well-structured answers.
- Build exam confidence: Solving multiple papers under timed conditions can reduce exam-day anxiety.
CBSE Class 12 Biology Board Exam 2027 Preparation Tips
Students preparing for the CBSE Class 12 Biology board exam should first complete the prescribed syllabus and revise each chapter thoroughly. NCERT Biology should remain the primary textbook for preparation, particularly for definitions, diagrams, concepts and important biological processes.
After completing a chapter, students can solve previous-year questions and sample papers to test their understanding. Maintaining a separate list of frequently forgotten concepts, diagrams and terminology can also make the final revision more effective.
Students should also practise drawing and labelling important Biology diagrams neatly, as diagram-based questions can require precise labelling and presentation..
Also Read l CBSE Class 12 Sample Paper: Business Studies
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