BOTANY

Anatomy of Flowering Plants

1. Root System

  • Function: Anchors the plant in the soil, absorbs water and nutrients.

  • Types:

    • Taproot System: A single, thick primary root (e.g., carrots, turnips) that grows deeper into the soil.

    • Fibrous Root System: A network of thin roots that spread out (e.g., grasses), helps prevent soil erosion and allows for better nutrient absorption.

  • Root Structure:

    • Root Cap: Protects the meristem as the root pushes through the soil.

    • Root Hairs: Increase surface area for absorption of water and minerals.

2. Stem

  • Function: Supports the plant, holds leaves and flowers, and conducts water and nutrients.

  • Structure:

    • Nodes: Points where leaves are attached.

    • Internodes: Sections of the stem between nodes.

  • Types:

    • Herbaceous Stem: Soft, green stems that are not woody (e.g., sunflowers).

    • Woody Stem: Hard, rigid stems that develop bark (e.g., trees).

  • Vascular Tissue:

    • Xylem: Transports water and minerals from roots to leaves.

    • Phloem: Distributes sugars produced by photosynthesis from leaves to other parts of the plant.

3. Leaves

  • Function: Main site for photosynthesis, gas exchange, and transpiration.

  • Structure:

    • Blade: The flat, green part that maximizes sunlight absorption.

    • Petiole: The stalk that connects the blade to the stem.

    • Stomata: Small openings on the underside of leaves for gas exchange.

  • Types:

    • Simple Leaves: Have one leaf blade (e.g., maple leaves).

    • Compound Leaves: Composed of multiple leaflets (e.g., clover leaves).

4. Flowers

  • Function: The reproductive structures that facilitate pollination and reproduction.

  • Structure:

    • Sepals: Protect the flower bud before it opens.

    • Petals: Often colorful, attracting pollinators.

    • Stamens: Male reproductive part, consisting of anther (produces pollen) and filament (supports anther).

    • Carpels: Female reproductive part, consisting of stigma (receives pollen), style (connects stigma and ovary), and ovary (contains ovules).

  • Pollination: Transfer of pollen from anther to stigma, can occur via wind, insects, or animals.

5. Fruits

  • Function: Develop from fertilized flowers, enclose seeds, and aid in dispersal.

  • Structure:

    • Made up of pericarp (tissue surrounding the seeds), which can have three layers—exocarp (outer), mesocarp (middle), and endocarp (inner).

  • Types:

    • Fleshy Fruits: Soft and edible (e.g., apples, peaches).

    • Dry Fruits: Hard or papery once mature (e.g., nuts, legumes).

  • Seed Dispersal: Mechanisms include wind, water, animals, and bursting from the fruit.

Anatomy of Flowering Plants (NEET Pattern)

Root System

  • Function:

    • Anchors the plant in soil

    • Absorbs water and nutrients

  • Types:

    • Taproot System: Single, thick primary root (e.g., carrots, turnips).

    • Fibrous Root System: Network of thin roots (e.g., grasses); prevents soil erosion.

  • Structure:

    • Root Cap: Protects meristem during soil penetration.

    • Root Hairs: Increase surface area for absorption of water/minerals.

Stem

  • Function:

    • Supports plant structure

    • Conducts water/nutrients

  • Types:

    • Herbaceous Stem: Soft and green (e.g., sunflowers).

    • Woody Stem: Hard, rigid; develops bark (e.g., trees).

  • Vascular Tissue:

    • Xylem: Transports water/minerals from roots to leaves.

    • Phloem: Distributes sugars from leaves to other plant parts.

Leaves

  • Function:

    • Main site for photosynthesis, gas exchange, and transpiration.

  • Structure:

    • Blade: Flat, green part for sunlight absorption.

    • Petiole: Stalk connecting blade to stem.

    • Stomata: Openings for gas exchange on leaf underside.

  • Types:

    • Simple Leaves: One leaf blade (e.g., maple leaves).

    • Compound Leaves: Multiple leaflets (e.g., clover leaves).

Flowers

  • Function:

    • Reproductive structures facilitating pollination and reproduction.

  • Structure:

    • Sepals: Protect flower bud before opening.

    • Petals: Colorful, attract pollinators.

    • Stamens: Male reproductive part (anther and filament).

    • Carpels: Female reproductive part (stigma, style, ovary).

  • Pollination: Transfer of pollen from anther to stigma via wind, insects, or animals.

Fruits

  • Function:

    • Develop from fertilized flowers, enclose seeds, aid in dispersal.

  • Structure:

    • Pericarp: Tissue surrounding seeds; layers include exocarp, mesocarp, endocarp.

  • Types:

    • Fleshy Fruits: Soft/edible (e.g., apples, peaches).

    • Dry Fruits: Hard/papery when mature (e.g., nuts, legumes).

  • Seed Dispersal: Mechanisms include wind, water, animals, bursting from fruit.