Purpose

• Seeds are the result of fertilization of a flower, whether it is edible or ornamental. Fertile seeds are future plants, containing all of the genetic coding necessary to produce another plant of the type that produced them. Selective pollination produces hybrid seeds, combining preferred genetic features of different plant varieties. The plant kingdom employs a variety of techniques to ensure dispersion of seeds and propagation of the plant.
  
  

Parts

• Labeled photo of dicotyledon seed (a bean).
  
  Seeds are covered in a protective coat, the testa. The hilum is the scar on one side of the seed that marks where it was attached to the seed pod. A tiny opening at one end of the hilum is the micropyle, the way the pollen tube entered the ovule to fertilize it and begin the creation of the seed. Within the testa is one (for monocot plants) or two (for dicot plants) cotyledons, the "seed leaves" or first leaves to develop as the seed germinates. The infant root and additional leaf attach to one of the cotyledons.
  
  

Types

• Monocot plants produce a single cotyledon, or seed leaf, as they germinate. Plants such as corn make up the monocotyledon plants. At germination, a single leaf appears. Dicotyledonous plants, such as beans, present with two seed leaves that are the two "halves" of the seed.
  
  

Dissemination

• Eat an apple or a watermelon and you are eating the ovary of the plant. The seeds develop in an array within the fruit. The fruit is eaten and the seeds discarded. Enjoy beans or peas and you are eating the seed itself, shucked from the pod in which it developed. Seeds travel when they are eaten as part of an animal's meal and later excreted as waste, or by adhering to a passing animal and falling off in another location. Some are windborne, carried to a new location by air currents. Animals carry some away and bury them, intending them for future food. Purchase a package of seeds at the local hardware or garden store and help disseminate seeds in less "natural" ways.
  
  

Pollinization

• Fertilize a flower from the same variety and seeds develop which will produce other plants of that variety, with all the strengths and weaknesses inherent in it. Pollinate a flower with another variety of the same species and the resulting plant may be stronger and healthier than either of the two parent varieties. These "hybrids" often result in greater yield yet are sterile, unable to produce seeds of their hybridized variety. Each new generation must be cross-pollinated. Develop a hybrid that produces viable seeds of its own variety to achieve a self-propagating variety. "The hybrids and their offspring should suffer no marked disturbance in their fertility in the successive generations," wrote Gregor Mendel, the historic father of the study of genetics. Some hybrids are produced by intentionally crossbreeding varieties possessing complementary strengths; others are accidents of nature.