Instead, it stated that the decision to get routine screening mammograms before age 50 should be an individual one and take patient context into account, including the patient's values regarding specific benefits and harms..
The seed coat helps protect the embryo from mechanical injury, predators and drying out. Depending on its development, the seed coat is either bitegmic or unitegmic. Bitegmic seeds form a testa from the outer integument and a tegmen from the inner integument while unitegmic seeds have only one integument.
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.his 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.