Reproduction From Seeds

Key Notes:

Introduction to Reproduction in Plants

  • Reproduction: The process by which plants produce new plants of the same kind.
  • Seeds: The primary method of reproduction in most plants.

Parts of a Seed

  • Seed Coat: The outer protective layer of the seed.
  • Embryo: The baby plant inside the seed that develops into a new plant.
  • Cotyledons: Also known as seed leaves, these store food for the growing embryo.
  • Endosperm: In some seeds, it serves as additional food storage.

Germination Process

  • Germination: The process by which a seed develops into a new plant.
  • Conditions for Germination:
    • Water: Activates enzymes that begin the growth process.
    • Oxygen: Needed for respiration during growth.
    • Warmth: Necessary for the enzymes to function properly.

Steps of Germination

  • Water Absorption: The seed absorbs water and swells.
  • Breaking of the Seed Coat: The seed coat breaks open, allowing the embryo to grow.
  • Growth of the Radicle: The radicle, or the embryonic root, emerges first and grows downward into the soil.
  • Shoot Emergence: The shoot, which contains the stem and leaves, grows upward towards the light.

Types of Seeds

  • Monocotyledons (Monocots): Seeds with one cotyledon (e.g., wheat, corn).
  • Dicotyledons (Dicots): Seeds with two cotyledons (e.g., beans, peas).

Seed Dispersal

  • Importance: Prevents overcrowding and ensures that plants can grow in different areas.
  • Methods of Seed Dispersal:
    • Wind Dispersal: Seeds are light and have wings or fluff (e.g., dandelion).
    • Water Dispersal: Seeds float and are carried by water (e.g., coconut).
    • Animal Dispersal: Seeds are carried by animals, either by attaching to fur or being eaten and excreted (e.g., berries).
    • Self-Dispersal: Some plants eject their seeds forcefully (e.g., peas).

Importance of Seeds

  • Food Source: Seeds are a primary food source for humans and animals (e.g., grains, nuts).
  • Plant Survival: Seeds ensure the survival of plant species by allowing plants to reproduce and spread.

Seed Conservation

  • Seed Banks: Facilities that store seeds to preserve plant diversity and protect against loss of plant species.

Let’s practice!