CBSE Class 12 Biology sample papers and practice questions

Sample papers work best after you have revised each chapter. Below are a few Biology MCQs with answers to check yourself. LerkAI can then create a full practice paper in your board's style for any mix of the 16 chapters, time you, and explain every wrong answer. These are practice papers made by LerkAI, not official CBSE papers, so also solve your board's official sample papers.

How to use this page

  1. Choose the chapters you have finished revising.
  2. Generate a timed practice paper with board-style marks.
  3. Attempt it in one sitting without notes.
  4. Read the explanation for every wrong answer and practise your weakest chapter again.

Practice questions with answers

  1. The enzyme that joins DNA fragments is:

    Answer: DNA ligase. DNA ligase seals nicks by forming phosphodiester bonds.

  2. Double fertilisation is a characteristic of:

    Answer: Angiosperms. Only angiosperms show syngamy plus triple fusion.

  3. In the lac operon, the inducer is:

    Answer: Lactose. Lactose (allolactose) binds the repressor and switches the operon on.

Chapters

  1. Reproduction in Organisms
  2. Sexual Reproduction in Flowering Plants
  3. Human Reproduction
  4. Reproductive Health
  5. Principles of Inheritance and Variation
  6. Molecular Basis of Inheritance
  7. Evolution
  8. Human Health and Disease
  9. Strategies for Enhancement in Food Production
  10. Microbes in Human Welfare
  11. Biotechnology: Principles and Processes
  12. Biotechnology and its Applications
  13. Organisms and Populations
  14. Ecosystem
  15. Biodiversity and Conservation
  16. Environmental Issues

Frequently asked questions

Are these official CBSE sample papers?

No. LerkAI creates practice papers in a board-like pattern. Always also solve the official CBSE sample papers.

How many questions can a practice test have?

You can create practice tests with up to 100 questions and an optional timer.

Does LerkAI explain wrong answers?

Yes. After each test you get an explanation for every question you got wrong.

Create a practice paper