ISC 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 9 chapters, time you, and explain every wrong answer. These are practice papers made by LerkAI, not official ISC 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 Lower and Higher Plants
  2. Reproduction in Lower and Higher Animals
  3. Genetics
  4. Evolution
  5. Human Health and Diseases
  6. Enhancement of Food Production
  7. Biotechnology
  8. Organisms and Environment
  9. Biodiversity and Conservation

Frequently asked questions

Are these official ISC sample papers?

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