A seed is the characteristic reproductive structure of plants, which includes a miniature plant (embryo) enclosed in a protective shell called the testa. Embryos also contain endosperm, a supply of nutrients for the embryo during development.
Seeds serve many important functions for plants, such as multiplication and dispersal to a new location. In addition, seeds often undergo periods of dormancy during unfavorable conditions.
Origin
Seeds are the reproductive parts of plants that can grow into new plants. They are usually made up of an embryo, a supply of nutrients, and a covering called the seed coat.
Seed plants are the most diverse lineage of vascular plants. They occur in a wide variety of environments and dominate today’s flora.
Many seed plants produce fruits that attract animals and help them spread the seeds around. Others have wing-like structures that aid wind dispersal, or seeds that attach to animal fur and drop off later.
These different methods of dispersal allow seed plants to occupy a variety of habitats. They also provide a variety of uses for plants and for people, such as food (cereals, legumes), fibers, and nonfood oils.
Parts
Seeds contain a number of different parts, including the seed coat, testa, plumule, radicle, embryo, and one or two cotyledons. These parts are used to store food for the seed embryo as it grows into a plant.
The embryo is the most important part of a seed and contains all of the cells that a plant needs to develop. It includes the epicotyl (a tiny shoot), hypocotyl (a transition zone between the rudimentary root and the growing shoot), radicle, and one or two cotyledons in monocot seeds.
The seed coat is the protective outer layer of a seed that is typically hard, thick and brown in colour. It is made from the integument of the ovule and consists of 2 layers: i) testa, the thick outer layer and ii) tegmen, the more delicate inner layer. On some seed coats, a small opening is visible at one end called the micropyle. In addition, there may be a scar on the seed coat called the hilum where the seed is attached to the ovary wall by the funiculus.
Function
Seeds serve several functions for the plants that produce them. These include nourishment of the embryo, dispersal to a new location, and dormancy during unfavorable conditions.
Almost all seeds have an embryonic plant enclosed within a protective coating called the seed coat. The seed coat protects the embryo against oxidative stress and also helps it to grow better once it is dispersed in soil.
In angiosperms, seed development begins with fertilization of the ovule and ends with formation of the endosperm. The endosperm develops from the zygote and is normally triploid, while the seed coat is formed from tissue derived from the integuments of the ovule.
Increasing consumption of a variety of seeds, including whole grains, nuts, legumes, and cocoa products has been shown to reduce cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM) risk. The benefits of seeds are attributed to their complex matrices of bioactive nutrients and phytochemicals that synergistically impact various metabolic pathways intermediate in CVD risk.
Uses
Seeds have many uses, including food, plant breeding, and horticulture. They are also used in medicine and oil production.
They are an important part of the food supply for both humans and animals. Most of the calories we get from foods are from seeds.
When a seed is planted, it will produce an embryo (embryo is the female part of a flowering plant that produces offspring) and endosperm, which store food that helps the new plant begin to grow. A tough outer covering, called a testa, protects the embryo and endosperm from damage from insects or other outside factors.
Seeds are a common source of food for people around the world, including grains such as wheat and corn, legumes such as beans and lentils, and nuts such as almonds and peanuts. They are also used in food processing and animal feed.
