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polymorphism



  1. (BIOLOGY) The existence of two or more types of individual within a single secies. For example, some social insects, such as the ant and bee, have several polymorphic types of worker adapted structurally to perform different tasks wthin their colony. Fowers can also assume more than one form.

  2. (GENETICS) A common variation in the sequence of DNA among individuals.

  3. (CHEMISTRY) 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