Seed Formation and Types

Seed Formation

• Seeds are formed from a zygote.
• Seeds have two layers.
• The outer layer is called the testa.
• The inner layer is called the tegmen.

Types of Seeds

• Endospermic seeds: These seeds have endosperm. Endosperm is the nutritive tissue that provides nourishment for the developing embryo.
•   Albuminous seed or Endospermic seed: Seeds that contain endosperm.
• Non-endospermic seeds: These seeds do not have endosperm. The cotyledons store food for the developing embryo.
• Non-albuminous seed or Non-endospermic seed:  Seeds that do not contain endosperm. Food is stored in the cotyledons.
• Some seeds consume all the endosperm.

Seed Types

• Monocot seeds: Monocots have one cotyledon (embryonic leaf).
• Dicot seeds: Dicots have two cotyledons.
• Dicots have a seed coat, hilum (scar where the ovule was attached to the ovary wall), micropyle (a small opening that allows water to enter the seed), cotyledons (seed leaves), radicle (the embryonic root), and plumule (the embryonic shoot).