Chapter 1: Reproduction in Organisms

CBSE Class 12 Biology PYQ Analysis (2021–2025)

Chapter Overview & Weightage

Most Important & Repeated Questions (2021–2025)

  • Repeated 4–5 times: Differentiate between asexual and sexual reproduction with examples. (2–3 marks)
  • Repeated 3–4 times: Explain different modes of asexual reproduction (binary fission, budding, fragmentation, vegetative propagation). (3–5 marks)
  • Repeated 3 times: What is vegetative propagation? Give examples of natural and artificial methods. (3 marks)
  • Repeated 2–3 times: Define life span. Give examples of organisms with different life spans (e.g., butterflies vs humans). (2 marks)
  • Repeated 2 times: What are pre-fertilization events? Explain gametogenesis and syngamy. (3 marks)
  • Assertion-Reason (2023–2025): Assertion: Asexual reproduction is common in unicellular organisms. Reason: It involves only mitosis. (Both true, reason explains – repeated 2x)

Important Keywords & Concepts to Memorize

  • Asexual reproduction, sexual reproduction, gametes, zygote, mitosis, meiosis, binary fission, budding, fragmentation, regeneration, spore formation, vegetative propagation, runner, rhizome, bulb, tuber, grafting, cutting, layering, tissue culture, life span, senescence, pre-fertilization events, gametogenesis, syngamy, embryogenesis, parthenogenesis, apomixis.

Exam Strategy for Chapter 1 (2026 Boards)

This is Chapter 1 complete PYQ analysis.
If you want the same for Chapter 2 or any other chapter, just say the chapter number or name.