Sexual Reproduction in Flowering Plants — Class 12 Biology NCERT Solutions (Free)

Free step-by-step NCERT solutions for Class 12 Biology chapter "Sexual Reproduction in Flowering Plants" — 8 important questions with detailed answers for CBSE board exam preparation.

TL;DR: Free step-by-step NCERT solutions for Class 12 Biology chapter "Sexual Reproduction in Flowering Plants" — 8 important questions with detailed answers…

By Syllab.in · Updated

Key Questions Covered:

  1. Define carpel and stamen.
  2. What is pollination? Distinguish between self-pollination and cross-pollination.
  3. Describe the structure of a pollen grain with the help of a labeled diagram d…
  4. What is double fertilization? Explain its significance in flowering plants.
  5. Describe the process of microsporogenesis and development of male gametophyte…
  6. Explain megasporogenesis and development of female gametophyte in angiosperms.
  7. + 2 more questions in the full chapter

Solutions Summary:

Question Status
Define carpel and stamen. ✓ Solved
What is pollination? Distinguish between self-pollination… ✓ Solved
Describe the structure of a pollen grain with the help of… ✓ Solved
What is double fertilization? Explain its significance in… ✓ Solved
Describe the process of microsporogenesis and development… ✓ Solved
Explain megasporogenesis and development of female gameto… ✓ Solved

Showing 6 of 8 questions

Q1: Define carpel and stamen.

Stamen is the male reproductive organ of a flower consisting of anther and filament. The anther produces pollen grains containing male gametes. Carpel is the female reproductive organ consisting of stigma, style, and ovary. The ovary contains ovules where female gametes develop.

Q2: What is pollination? Distinguish between self-pollination and cross-pollination.

Pollination is the transfer of pollen from anther to stigma. Self-pollination: Pollen from anther of one flower is transferred to stigma of the same flower or another flower of the same plant. Example: wheat, pea, tomato. Cross-pollination: Pollen from anther of one flower is transferred to stigma of a flower on a different plant of the same species. Example: maize, coconut, cucumber. Cross-pollination brings genetic variation and hybrid vigor.

Q3: Describe the structure of a pollen grain with the help of a labeled diagram description.

A pollen grain is a microscopic structure with thick protective wall: - Outer wall: exine (thick, sculptured, protects pollen) - Inner wall: intine (thin, flexible) - Cytoplasm containing: generative nucleus (smaller, will form sperm) and vegetative nucleus (larger, controls pollen tube growth) - Apertures: pores or furrows where intine is exposed, aid in pollen tube emergence The two-celled pollen has generative and vegetative nuclei; three-celled pollen has two sperm cells formed already.

Q4: What is double fertilization? Explain its significance in flowering plants.

Double fertilization is the fusion of two male gametes (sperm) with female gametophyte in angiosperms: - First fusion: one sperm fuses with egg cell forming diploid zygote (2n) that develops into embryo - Second fusion: second sperm fuses with two polar nuclei forming triploid central cell (3n) that develops into endosperm (nutritive tissue) Significance: - Ensures nutritive tissue develops only when embryo develops - Endosperm provides nutrition to developing embryo - Unique to flowering plan...

Q5: Describe the process of microsporogenesis and development of male gametophyte in flowering plants.

Microsporogenesis occurs in pollen sacs (anther lobes): 1. Microspore mother cells (diploid) undergo meiosis 2. Each microspore mother cell produces four haploid microspores 3. Microspores separate and develop thick wall Male gametophyte (pollen) development: 1. Nucleus of microspore undergoes first mitotic division forming generative and vegetative nuclei (two-celled pollen) 2. Pollen wall develops (exine and intine) 3. Before or after pollination, generative nucleus divides by mitosis formi...

Q6: Explain megasporogenesis and development of female gametophyte in angiosperms.

Megasporogenesis occurs in nucellus of ovule: 1. One megaspore mother cell (diploid) undergoes meiosis 2. Produces four haploid megaspores 3. Three degenerate; one functional megaspore survives Female gametophyte (embryo sac) development (most common type - Polygonum): 1. Functional megaspore nucleus undergoes three mitotic divisions 2. Forms eight nuclei arranged in seven-celled stage: - Egg apparatus at micropylar end: one egg cell (female gamete) and two synergids (help guide pollen tub...

Showing 6 of 8 questions. Visit the full page for complete solutions.

More Class 12 Biology NCERT Solutions