CBSE Class 12 Biology Sample Papers 2026-27

Prepare for your Class 12 CBSE Biology board exam with 20 full-length sample papers, each modelled on the prescribed question paper pattern: 33 questions across five sections, 70 marks, 3-hour format. 332 pages, with a model answer key after every paper.

What's Inside

Each paper follows the five-section structure: Section A (16 questions, 1 mark each, twelve multiple choice and four Assertion-Reason), Section B (5 questions, 2 marks each), Section C (7 questions, 3 marks each), Section D (2 case-based questions, 4 marks each), and Section E (3 questions, 5 marks each). There is no overall choice, and internal choices are provided in some questions, as in the board paper.

The book carries 117 full-colour diagrams built into the questions rather than printed as decoration. Figures include hormone levels across the menstrual cycle, the DNA double helix with an annotated key-features panel, Punnett squares for dihybrid crosses, sewage treatment flow diagrams, ecological pyramids, food webs, the genetic code table, spermatogenesis stages and restriction enzyme action. Questions ask you to read the figure and answer from it, which is how diagram marks are earned in the exam.

Case-based questions are set out as a boxed scenario followed by linked sub-questions: a couple seeking IVF, a family referred for genetic counselling after a thalassaemia diagnosis, an organ transplant patient on immunosuppressants, the collapse of the Aral Sea ecosystem. Each asks you to apply syllabus concepts to a situation rather than recall them.

Answer keys give worked model answers with marking notes, not one-line responses. Objective answers carry a short explanation of why the option is right. Longer answers are written to the depth and length a full-mark response needs, and comparison answers are set out as proper tables. A ▲ beside an answer marks a question that is commonly answered incorrectly, so you know which ones to review first.

Topics Covered

All units of the Class 12 Biology syllabus. Reproduction: sexual reproduction in flowering plants including pollination, double fertilisation and apomixis, human reproduction, the menstrual cycle, spermatogenesis and oogenesis, and reproductive health including contraception and assisted reproductive technologies. Genetics and Evolution: Mendelian inheritance, dihybrid crosses, linkage, sex-linked disorders and pedigree analysis, chromosomal disorders, the molecular basis of inheritance covering DNA packaging, replication, the Meselson-Stahl experiment, transcription, the genetic code, translation and the lac operon, plus Hardy-Weinberg equilibrium, natural selection and the evidence for evolution. Biology in Human Welfare: human health and disease, immunity and the immune response, vaccination, cancer, drug and alcohol abuse, and microbes in sewage treatment, biogas and biocontrol. Biotechnology: recombinant DNA technology, restriction endonucleases, gel electrophoresis, PCR, cloning vectors, Bt cotton, RNA interference and gene therapy. Ecology: population growth including exponential and logistic models, age pyramids, species interactions and resource partitioning, ecosystems and energy flow, the ten per cent law, ecological pyramids, succession, biodiversity hotspots and conservation.

Difficulty Levels

Papers are printed in ascending order of difficulty: Easy (Papers 1–6), Medium (Papers 7–14) and Hard (Papers 15–20), so you can work straight through the book. The level is printed on each paper's first page, on its answer key, and in the Contents.

At a Glance

• 20 full-length sample papers, 332 pages

• 33 questions per paper (70 marks, 3 hours)

• Three difficulty levels in ascending order: Easy, Medium, Hard

• Model answer key with marking notes after every paper

• 117 full-colour diagrams integrated into the questions

• Two case-based questions in every paper

• Assertion-Reason questions with the full option set

• Commonly-missed questions flagged in the answer keys

• Internal choice, as in the board paper

Disclaimer

This ebook is an independent publication by FutureTopper.in and is not affiliated with, endorsed by, or associated with the Central Board of Secondary Education (CBSE), NCERT or any government body. These papers are designed for practice and self-assessment only and do not represent actual board examination papers. Diagrams are original schematic teaching aids. While care has been taken to ensure accuracy, minor errors may exist. Errors can be reported to contactfuturetopper@gmail.com.