A seed is a tiny part of a plant that gives rise to a new plant. It can be a pip, a nut, or a bean. Let’s find out more about it. It is an important part of a flowering plant. It gives rise to a new plant. It may be of different shapes, colors, and sizes. They may be round, wrinkled, winged, or hairy. They are in a dormant condition until they receive adequate sunlight, water, and soil.
3 Main Parts of a Seed
The growth of the plant from the seeds is known as germination. It has 3 main parts:
- Seed Coat
1. Seed Coat: A seed coat protects the internal parts of the seeds. It has two layers. The outer layer is thick and known as the testa. The inner layer is thin and known as tegmen. A thick seed coat protects the seeds from sunlight and water. It prevents the loss of water and entry of parasites within the seeds. The hard seed’s coats prevent germination during unfavorable environmental conditions. An opening in the integument of the ovule is known as the micropyle and is visible on some seed coats.
- Protect the seeds from physical and mechanical damage.
- Preventing the seeds from germination even under favorable conditions of growth.
- Protecting the excessive loss of water from the seeds.
- Acting as a physical barrier against the entry of parasites.
2. Endosperm: The endosperm contains the nutrients stored in it. It provides nutrients to the seed in the form of starch, carbohydrates, and proteins to support the embryo during germination. It is located below the seed coat. The seeds remain viable with the intake of nutrients until germination. In corns and other cereals, endosperm constitutes a major portion of the seed. In seeds like beans, the endosperm is utilized in the embryo development and is absent in the seed. Coconut is the liquid endosperm.
3. Embryo: The embryo is the most important part of a seed. It is diploid, developed from the fertilized egg. All the cells that need to develop into a mature embryo are present within the embryo. An embryo comprises the following parts:
- Epicotyl: It is a small shoot that gives rise to the entire plant shoot system.
- Hypocotyl: The stage of transition for the growing shoot and root of the embryo
- Radicle: The tiny root of the embryo
- Cotyledons: They are the leaves of the embryo that provide nourishment to the developing plant.
Functions of Embryo
- Giving rise to a new completely new plant.
- Storing food and nourishing the baby plant.