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polymorphism



  1. In zoology and botany, polymorphism is the existence of two or more types of individual within a single species. For example, some social insects, such as the ant and bee, have several polymorphic types of worker adapted structurally to perform different tasks within their colony. Flowers can also assume more than one form.

  2. In genetics, polymorphism is a common variation in the sequence of DNA among individuals.

  3. In chemistry, polymorphism is the existence of certain chemical compounds in more than one crystalline form (see crystal). Usually the various forms are stable under different conditions. In some cases one is always stable, the others being metastable; thus calcium carbonate has a stable hexagonal form calcite and a metastable orthorhombic form aragonite. See also allotropy.

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   • GENETICS AND HEREDITY
   • INORGANIC CHEMISTRY
   • ORGANIC CHEMISTRY