CBSE Class 12 Biology Board Exam Preparation
Genetics, evolution, ecology, and biotechnology — the complete board strategy
Complete chapter-wise preparation guide for CBSE Class 12 Biology board exam. Reproduction, genetics, evolution, human health, biotechnology, and ecology — with chapter-wise marks and proven exam strategy.
Practice with AI Evaluation →70
Theory Marks
30
Practical Marks
3 hours
Exam Duration
13
Total Chapters
Chapter-Wise Marks Breakdown
70 theory marks| Chapter | Marks | Difficulty |
|---|---|---|
| Sexual Reproduction in Flowering Plants | 8 | Hard |
| Human Reproduction | 6 | Hard |
| Reproductive Health | 2 | Easy |
| Principles of Inheritance and Variation | 8 | Hard |
| Molecular Basis of Inheritance | 8 | Hard |
| Evolution | 4 | Medium |
| Human Health and Diseases | 7 | Medium |
| Microbes in Human Welfare | 5 | Easy |
| Biotechnology: Principles and Processes | 6 | Hard |
| Biotechnology and its Applications | 6 | Medium |
| Organisms and Populations | 4 | Medium |
| Ecosystem | 4 | Medium |
| Biodiversity and its Conservation | 2 | Easy |
Exam Resources
Topics That Appear Every Year
Study Strategy for 90+
Genetics and Molecular Biology together carry 16 marks — highest priority unit
Diagrams are 30% of Biology marks — draw every important structure from memory
Biotechnology PCR and rDNA technology: learn all steps in exact sequence
Ecology: ecological pyramids and energy flow are asked every year
Reproductive chapters need both diagram labelling and functional understanding
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ClearSteps gives you CBSE Class 12 Biology mock papers, concept videos for every chapter, and AI evaluation against the real CBSE marking scheme.