Important Questions for Class 12 Biology (Chapter-wise, Free)
Important questions and high-weightage chapters for Class 12 Biology — chapter-wise key topics with free practice. CBSE/NCERT-aligned.
TL;DR: Important questions and high-weightage chapters for Class 12 Biology — chapter-wise key topics with free practice. CBSE/NCERT-aligned.
Written & reviewed by the Syllab.in Academic Team (CBSE/NCERT subject experts) · Updated
Chapter-wise important questions for Class 12 Biology. 8 chapters are covered below, 5 with past-year questions and 1 with objective practice — every link goes to a full set with worked solutions, free and without a login.
Where the Marks Are — Class 12 Biology
Class 12 Biology is 70 marks. Genetics & Evolution and Reproduction together carry nearly half.
| Unit | Marks | Focus on |
|---|---|---|
| Genetics & Evolution | 18 | Inheritance, molecular basis, evolution — the top-weighted unit. |
| Reproduction | 14 | Human + plant reproduction, reproductive health — diagram-heavy. |
| Biology in Human Welfare | 14 | Health, microbes, food production. |
| Biotechnology | 12 | Principles and applications — recall + process. |
| Ecology | 12 | Ecosystem, biodiversity — easy diagrams and definitions. |
Full marks weightage for Class 12 Biology →
Chapter-wise Important Questions
Each row links to the material that exists for that chapter. A dash means we do not have that format for the chapter yet — it is not a broken link.
| Chapter | Past-year questions | Objective / MCQs | Revision notes |
|---|---|---|---|
| Biotechnology and its Applications | PYQs | — | — |
| Ecosystem | PYQs | — | — |
| Genetics and Evolution | PYQs | — | — |
| Human Reproduction | PYQs | — | Notes |
| Principles of Inheritance and Variation | — | — | Notes |
| Reproduction | — | — | Notes |
| Reproduction and Development | — | MCQs | — |
| Reproduction in Organisms | PYQs | — | — |
How to Work Through These
Take the chapters in order of marks, not in order of the textbook. For each one, read the revision notes to fix the ideas, then do the past-year questions under time — those show you the phrasing examiners actually use, which is usually narrower than the chapter itself. Objective questions are best left for the last week, when they become a fast way to find gaps rather than a way to learn.
A chapter is finished when you can produce the answer without looking, not when you have read the solution and agreed with it.
Frequently Asked Questions
Which chapters are most important for Class 12 Biology?
By marks, Genetics & Evolution (18), Reproduction (14), Biology in Human Welfare (14) carry the most in the board paper — see the weightage table above. Within those, the chapters listed below with past-year questions are the ones examiners have actually returned to.
How should I use important questions when revising?
Read the chapter first, then attempt its questions closed-book, and only then check the solutions. Working the questions before revising the chapter tells you what you do not know, which is useful; working them with the answers open tells you nothing at all.
Are previous year questions available for Class 12 Biology?
Yes — 5 of the 8 chapters listed have a past-year question set with worked solutions, linked in the table above.
All Class 12 subjects → · Full-length sample papers → · All previous-year questions →