What is Seed Structure and Dispersal?

A seed develops from a fertilized ovule and protects the embryo of a new plant. Seeds may carry food reserves and delay development until conditions are suitable.

What parts make up a seed?

A seed contains an embryo, a seed coat around it, and in many species a food-storage tissue that supports early growth. The amount and location of this tissue vary; in some plants, most reserves are stored in the embryo’s cotyledons. The seed coat helps protect the embryo from physical damage and water loss. In flowering plants, seeds develop after fertilization; in gymnosperms, seeds form on cone scales. Seed size, shape, and dormancy relate to strategies for dispersal and germination.

How are seeds dispersed?

Seeds can travel away from the parent plant by wind, water, animals, and gravity; in some species, fruits open and scatter them. Dispersal can reduce competition with the parent plant for light, water, and space and can help seeds reach new habitats. Not every seed travels far. Even when conditions seem suitable, viability, dormancy, and environmental factors determine whether germination occurs. Seed packet instructions are species-specific; it is not appropriate to sow all seeds at the same depth or temperature.