Seeds are the reproductive structures of plants that carry all of the information required to grow into a new plant. They contain food and instructions for the embryo inside a hard shell. Seeds can be used to propagate many crops, including cereals, legumes and forest trees.
A seed needs water and nutrients to start growing. But how does it get them?
Seeds are a form of reproduction
Seeds are the means by which plant species reproduce, preserve themselves, increase their numbers, and disperse. They are an example of the complication that nature has devised to ensure that each plant species survives in its ecosystem. Scientists at The New York Botanical Garden are working to understand how seeds work. They are looking at genes that control the development of seeds and ovules.
Seed germination is a process that starts with the absorption of water. This reactivates enzymes that break down storage compounds and makes them available to the embryo inside the seed. Barley, for example, uses this process to convert starch into sugars.
This is a much faster and more efficient process than the more primitive way that plants like mosses and liverworts reproduce, using unprotected single-celled spores. The advantage of seed over spores is that it contains a reserve of nutrients for the new plant to grow on. It also has a multicellular structure, which allows it to develop adaptations for dispersal, such as plumes or burrs to hook onto animals’ fur or feathers, for example.
They are a source of food
Seeds are an important source of food and a rich source of nutrients. They contain healthy fatty acids, vitamins and minerals, including folate, vitamin E, and antioxidants. They also provide protein and dietary fiber. A small daily serving of seeds is recommended for health and well-being.
Seeds serve several purposes for the plants that produce them: they nourish an embryo or a seedling, disperse the seed to a new location, and store food until germination is possible. They often have hard outer coatings that are nutrient rich, and they can survive harsh conditions. Some have special hooks or burrs to attach to fur or beaks so they can be carried long distances, while others are dispersed by wind or water currents.
Seeds can be eaten raw, toasted, or ground to make flour. They are an excellent source of fibre, which reduces the risk of heart disease, bowel cancer, Type-2 diabetes, and high blood pressure. They are also a rich source of essential fatty acids, phytoestrogens, and isoflavones.
They are a source of energy
Seeds are the characteristic reproductive structure of both angiosperms (flowering plants) and gymnosperms (conifers, cycads, and ginkgoes). They comprise a miniature undeveloped plant embryo and stored food reserves, enclosed in a hard or soft seed coat. Seeds provide a number of important functions, including nourishment of the embryo, dispersal to a new location, and dormancy during periods of unfavorable conditions.
In addition to the embryo and its food supply, seeds contain water, which provides essential moisture to the seedling when it emerges from the ground. They also contain one or more cotyledons, which are the first leaves of the seedling. These leaves are a source of energy and help the seedling to begin photosynthesis. Seeds are also a rich source of vitamins and minerals, especially when they are eaten in moderation. However, excessive consumption can lead to weight gain. Some seeds have developed adaptations for dispersal, such as hooks to catch on fur and burrs to latch onto twigs and branches.
They are a form of germination
Germination is the process by which seeds of a plant sprout into seedlings or plants. The seed contains all the genetic information for a new plant, but it must be in the right conditions to grow into a new plant. Seeds may be carried by animals (such as birds or bats) or by wind and water. They also can be spread by ants, fungi or bacteria.
To germinate, a seed must have water, dissolved oxygen and some food. The food supply in the seed is called endosperm and consists of starch, sugars, oils and proteins. During the process of germination, the seed reactivates enzymes and breaks down these storage compounds into soluble form. This enables the embryo to resume growth during the establishment phase of the plant.
The first stage of germination is the uptake of water by the seed, which is known as imbibition. This reactivates the enzymes that break down the stored food and releases water into the embryo. This uptake of water causes the seed coat to rupture and exposes the radicle, plumule and cotyledons.
