Cue Column | Note-Taking Area
| Cue | Notes |
|---|---|
| What are the 4 whorls of a flower? | Calyx (sepals) → Corolla (petals) → Androecium (stamens) → Gynoecium (pistils) — outer to inner |
| Stamen structure? | Filament (stalk) + Anther (pollen-producing head containing microsporangia) |
| Pistil structure? | Stigma (receives pollen) + Style (tube) + Ovary (contains ovules) |
| Microsporogenesis? | PMC (2n) → meiosis → microspore tetrad (each n) → pollen grain (2-celled: vegetative + generative) |
| Megasporogenesis? | MMC (2n) → meiosis → 4 megaspores → 3 degenerate, 1 functional megaspore |
| Embryo sac development? | Functional megaspore → 3 free nuclear mitotic divisions → 8 nuclei → 7-celled, 8-nucleate embryo sac |
| Embryo sac organization? | Micropylar end: egg + 2 synergids; Middle: central cell (2 polar nuclei); Chalazal end: 3 antipodals |
| Pollination types? | Autogamy (same flower) |
| Double fertilization? | Syngamy: sperm + egg = zygote (2n); Triple fusion: sperm + 2 polar nuclei = PEN (3n) |
| Post-fertilization fate? | Ovule → seed; Ovary → fruit; Integuments → seed coat; PEN → endosperm; Zygote → embryo |
| Outbreeding devices? | Self-incompatibility, dicliny, dichogamy |
| Apomixis? | Seeds without fertilization (clonal offspring) |
| Parthenocarpy? | Seedless fruit without fertilization |
Summary
Sexual reproduction in flowering plants involves microsporogenesis (pollen production), megasporogenesis (embryo sac formation), pollination (pollen transfer), and double fertilization (syngamy + triple fusion). The key NEET facts: embryo sac is 7-celled/8-nucleate; endosperm is 3n (triploid); geitonogamy is genetically self-pollination.
Diagram
