🌸 Reproductive Parts of Flowers

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 🌸 Reproductive Parts of Flowers

Structure of Anther (T.S. of an angiospermic anther)

Characters:

  1. The structure is four-chambered in transverse section.

  2. Wall consists of:

    • Outer epidermis

    • Endothecium

    • 1–3 middle layers

    • Innermost tapetum

  3. Tapetum: multinucleate, dense cytoplasm, nourishes pollen.

  4. Endothecium: radially elongated cells with fibrous thickenings (helps in dehiscence).

  5. Microspores: present as tetrads or as individual pollen grains.

👉 Identified as T.S. of an angiospermic anther.

📷 Diagram: Four-chambered anther showing epidermis, endothecium, tapetum, sporogenous tissue, stomium, conducting strand.

🌱 Ovules

The ovule is located inside the ovary, attached by a funiculus to the placenta.
It has:

  • Nucellus (with embryo sac)

  • Covered by integuments

  • An opening called micropyle

Types of Ovules

1️⃣ Orthotropous ovule (e.g., Polygonum)

  • Straight ovule.

  • Micropyle, chalaza, and funiculus in one vertical line.
    👉 Identified as Orthotropous ovule.

📷 Diagram: Straight ovule with embryo sac.

2️⃣ Anatropous ovule (e.g., Datura)

  • Inverted ovule, curved 180°.

  • Micropyle lies near funiculus.

  • Micropyle & chalaza in straight line, funiculus forms a raphe.
    👉 Identified as Anatropous ovule.

📷 Diagram: Inverted ovule with raphe & funiculus.

3️⃣ Campylotropous ovule (e.g., Pisum/Pea)

  • Ovule body at right angle to funiculus.

  • Curvature 90°–160°.

  • Micropyle comes towards funiculus.

  • Embryo sac straight/slightly curved.
    👉 Identified as Campylotropous ovule.

📷 Diagram: Curved ovule with embryo sac.

👉🔬 Intermediate Practical Book 

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