Seed coat. It is an embryonic plant enclosed in a protective outer covering known as the seed coat.
seed potatoes, seeds of corn or sunflower seeds . In the case of sunflower and corn seeds, what is sown is the seed enclosed in a shell or husk, whereas the potato is a tuber. Many structures commonly referred to as seeds are actually dry fruits. The seed coat in the mature seed can be a paper-thin layer (e.g. peanut) or something more substantial (e.g. thick and hard in honey locust and coconut), or fleshy as in the sarcotesta of pomegranate. The seed coat helps protect the embryo from mechanical injury, predators and drying out. An untouched coconut has three layers. The outermost layer, which is typically smooth with a greenish color, is called the exocarp. The next layer is the fibrous husk, or mesocarp, which ultimately surrounds the hard woody layer called the endocarp. The endocarp surrounds the seed. Coconuts are classified as a fibrous one-seeded drupe. A drupe is a fruit with a hard stony covering enclosing the seed (like a peach or olive) and comes from the word drupa meaning overripe olive. Seed germination is a process by which a seed embryo develops into a seedling. It involves the reactivation of the metabolic pathways that lead to growth and the emergence of the radicle or seed root and plumule or shoot. The seed coat in the mature seed can be a paper-thin layer (e.g. peanut) or something more substantial (e.g. thick and hard in honey locust and coconut), or fleshy as in the sarcotesta of pomegranate. The seed coat helps protect the embryo from mechanical injury, predators and drying out. Fruits are the mature ovary or ovaries of one or more flowers. In fleshy fruits, the outer layer (which is often edible) is the pericarp, which is the tissue that develops from the ovary wall of the flower and surrounds the seeds. But in some seemingly pericarp fruits, the edible portion is not derived from the ovary. The pericarp is typically made up of three distinct layers: the epicarp, which is the outermost layer; the mesocarp, which is the middle layer; and the endocarp, which is the inner layer surrounding the ovary or the seeds. In a citrus fruit, the epicarp and mesocarp make up the peel When a great deal of xylem accumulates, it is called wood; plants with wood may be trees, shrubs, or stout vines. Periderm is the other product of secondary growth; it is produced by the cork cambium, a cylindrical layer of cells which develops not far under the outer skin (epidermis) of the plant. This layer may be thick or thin, depending on the species, but it often contains light-sensitive chemicals. When conditions are right -- there is appropriate light and water -- the seed coat may trigger the germination of the seed. Plant Roots. The root system of a plant constantly provides the stems and leaves with water and dissolved minerals. In order to accomplish this the roots must grow into new regions of the soil. The growth and metabolism of the plant root system is supported by the process of photosynthesis occurring in the leaves. Photosynthate from the leaves is transported via the phloem to the root system. The seed contains and disperses the embryo. Around the whole seed is a layer called the seed coat. This layer may be thick or thin, depending on the species, but it often contains light-sensitive chemicals. When conditions are right -- there is appropriate light and water -- the seed coat may trigger the germination of the seed. A seed is an embryonic plant enclosed in a protective outer covering known as the seed coat. It is a characteristic of spermatophytes (gymnosperm and angiosperm plants) and the product of the ripened ovule which occurs after fertilization and some growth within the mother plant. The seed coat in the mature seed can be a paper-thin layer (e.g. peanut) or something more substantial (e.g. thick and hard in honey locust and coconut), or fleshy as in the sarcotesta of pomegranate. The seed coat helps protect the embryo from mechanical injury, predators and drying out. It is only when the egg cell inside the ovule is fertilized by sperm that the ovule is called a seed. The ovule is surrounded by integument tissues which produce the seed coat, and in the earliest seed plants another layer called the cupule enclosed the entire ovule / seed. This layer may be thick or thin, depending on the species, but it often contains light-sensitive chemicals. When conditions are right -- there is appropriate light and water -- the seed coat may trigger the germination of the seed.
https://en.wikipedia.org/wiki/Seed http://loc.gov/rr/scitech/mysteries/coconut.html https://en.wikipedia.org/wiki/Seed https://en.wikipedia.org/wiki/Fruit_anatomy http://www.ucmp.berkeley.edu/seedplants/seedplantsmm.html http://facweb.furman.edu/~lthompson/bgy34/plantanatomy/plant_root.htm http://www.ucmp.berkeley.edu/seedplants/seedplantsmm.html https://en.wikipedia.org/wiki/Seed http://www.ucmp.berkeley.edu/seedplants/seedplantsmm.html
what is a seed layer called