Chapter 2: Sexual Reproduction in Flowering Plants – Very Short Answer Type Questions

CBSE Class 12 Biology – Very Short Answer Questions with Answers

Unit I: Reproduction | Chapter 2: Sexual Reproduction in Flowering Plants (NCERT Based)

Course & Examination Details

• Course: CBSE Class 12 Biology
• Prescribed By: Central Board of Secondary Education
• Syllabus Source: NCERT
• Unit: Unit I – Reproduction
• Chapter: Chapter 2 – Sexual Reproduction in Flowering Plants
• Exam Relevance: CBSE Class 12 Board Examinations

CBSE Class 12 Biology Chapter 2 Very Short Answer Questions – Sexual Reproduction in Flowering Plants (NCERT)

Section A: Flower as a Reproductive Organ

Q1. What is a flower?
Ans: A flower is a modified shoot of angiosperms specialised for sexual reproduction, bearing male and female reproductive organs arranged in whorls.

Q2. Name the four floral whorls of a complete flower.
Ans: The four floral whorls are calyx, corolla, androecium, and gynoecium, arranged concentrically on the thalamus.

Q3. What is a bisexual flower?
Ans: A bisexual flower contains both androecium and gynoecium, enabling production of male and female gametes in the same flower.

Q4. What is a unisexual flower?
Ans: A unisexual flower bears either male or female reproductive organs, but not both, as seen in papaya.

Q5. State one function of petals.
Ans: Petals attract pollinators through bright colours, fragrance, or nectar, thereby facilitating pollination.

Section B: Structure of Stamen and Carpel

Q6. What are the two main parts of a stamen?
Ans: A stamen consists of a filament and an anther, together forming the male reproductive unit of a flower.

Q7. How many microsporangia are present in a typical anther?
Ans: A typical anther has four microsporangia, arranged as two in each anther lobe.

Q8. Name the nutritive layer of the anther wall.
Ans: The tapetum is the innermost anther wall layer that provides nourishment to developing pollen grains.

Q9. What are the three parts of a carpel?
Ans: A carpel consists of stigma, style, and ovary, forming the female reproductive organ of a flower.

Q10. Where are ovules located in a flower?
Ans: Ovules are located inside the ovary and are attached to the placenta.

Section C: Microsporogenesis and Pollen Grain

Q11. Define microsporogenesis.
Ans: Microsporogenesis is the process of formation of haploid microspores from diploid microspore mother cells through meiosis.

Q12. What is a microspore mother cell (MMC)?
Ans: MMC is a diploid cell in the anther that undergoes meiosis to produce four haploid microspores.

Q13. Name the outer wall of a pollen grain.
Ans: The outer wall of a pollen grain is called exine, composed of sporopollenin.

Q14. Why is sporopollenin important?
Ans: Sporopollenin makes pollen grains highly resistant to heat, enzymes, and harsh environmental conditions.

Q15. How many cells are present in a mature pollen grain?
Ans: A mature pollen grain usually contains one vegetative cell and one generative cell.

Section D: Megasporogenesis and Embryo Sac

Q16. Define megasporogenesis.
Ans: Megasporogenesis is the formation of haploid megaspores from a diploid megaspore mother cell by meiosis inside the ovule.

Q17. How many megaspores are formed initially?
Ans: Four haploid megaspores are formed, of which usually only one remains functional.

Q18. What is an embryo sac?
Ans: The embryo sac is the female gametophyte of angiosperms, developed from a functional megaspore.

Q19. How many cells are present in a typical embryo sac?
Ans: A typical embryo sac is seven-celled and eight-nucleate in structure.

Q20. Name the cells of the egg apparatus.
Ans: The egg apparatus consists of one egg cell and two synergids located at the micropylar end.

Section E: Pollination

Q21. What is pollination?
Ans: Pollination is the transfer of pollen grains from the anther to the stigma of a flower.

Q22. Name the three types of pollination.
Ans: The three types are autogamy, geitonogamy, and xenogamy.

Q23. Which type of pollination promotes genetic variation?
Ans: Xenogamy promotes genetic variation by transferring pollen between different plants of the same species.

Q24. Name one abiotic agent of pollination.
Ans: Wind is an abiotic agent of pollination, known as anemophily.

Q25. What is entomophily?
Ans: Entomophily is pollination carried out by insects attracted to flowers by nectar and fragrance.

Section F: Double Fertilisation

Q26. What is double fertilisation?
Ans: Double fertilisation involves syngamy and triple fusion occurring in the same embryo sac of angiosperms.

Q27. What is syngamy?
Ans: Syngamy is the fusion of one male gamete with the egg cell to form a diploid zygote.

Q28. What is triple fusion?
Ans: Triple fusion is the fusion of one male gamete with two polar nuclei, forming a triploid primary endosperm nucleus.

Q29. Why is double fertilisation unique to angiosperms?
Ans: Only angiosperms show fusion of two male gametes with different cells inside the embryo sac.

Q30. State one significance of double fertilisation.
Ans: It ensures simultaneous development of embryo and nutritive endosperm for efficient resource utilization.

Section G: Post-Fertilisation Changes

Q31. What does the ovule develop into after fertilisation?
Ans: After fertilisation, the ovule develops into a seed.

Q32. What does the ovary form after fertilisation?
Ans: The ovary develops into a fruit after fertilisation.

Q33. What is endosperm?
Ans: Endosperm is a nutritive tissue that provides nourishment to the developing embryo.

Q34. Name the most common type of endosperm development.
Ans: Nuclear endosperm development is the most common type in flowering plants.

Q35. What are cotyledons?
Ans: Cotyledons are embryonic seed leaves that store or absorb food for the developing seedling.

Section H: Seed and Fruit Formation

Q36. What is a true fruit?
Ans: A true fruit develops only from the ovary after fertilisation.

Q37. What is a false fruit?
Ans: A false fruit develops from the ovary along with other floral parts such as thalamus.

Q38. Name the protective covering of a seed.
Ans: The seed coat, consisting of testa and tegmen, protects the seed.

Q39. What is the function of the micropyle in a seed?
Ans: Micropyle allows entry of water and oxygen during seed germination.

Q40. Why is fruit formation important?
Ans: Fruits protect seeds and aid in seed dispersal.

Section I: Apomixis and Polyembryony

Q41. What is apomixis?
Ans: Apomixis is seed formation without fertilisation, producing genetically identical offspring.

Q42. Name one advantage of apomixis.
Ans: It preserves desirable hybrid characters over generations without genetic segregation.

Q43. What is polyembryony?
Ans: Polyembryony is the occurrence of more than one embryo within a single seed.

Q44. Name one plant showing polyembryony.
Ans: Citrus commonly shows polyembryony.

Q45. From which tissue can adventive embryos arise?
Ans: Adventive embryos may arise from nucellus or integuments.

Section J: Conceptual Understanding

Q46. Why are synergids important?
Ans: Synergids guide the pollen tube into the embryo sac through chemical signals.

Q47. What is the function of the pollen tube?
Ans: The pollen tube transports male gametes from pollen grain to embryo sac.

Q48. Why is pollination essential before fertilisation?
Ans: Pollination brings male gametes close to the female gamete, enabling fertilisation.

Q49. Which structure protects the developing embryo inside the seed?
Ans: The seed coat protects the developing embryo from physical damage and desiccation.

Q50. State the overall importance of sexual reproduction in flowering plants.
Ans: Sexual reproduction generates variation, ensures seed formation, and maintains continuity and adaptability of plant species.

CBSE Board Exam Note

These Very Short Answer Questions (20–30 words each) are strictly NCERT-based, aligned with CBSE Class 12 Biology board exam standards, and ideal for 1-mark concept questions and quick revision.