Definition

1. Noun:
   • (Biology): The occurrence of two or more distinct morphological forms or stages in the life cycle of an organism, or within a single species.
   • (Chemistry, Crystallography): The property of a substance, especially a chemical compound, to crystallize in two or more distinct forms with different structures.

Examples of Usage

• Noun (Biology):

  • The pleomorphism of certain fungi makes them difficult to classify.
  • Scientists studied the bacterial pleomorphism under different environmental conditions.

• Noun (Chemistry):

  • The pleomorphism of carbon is demonstrated by graphite and diamond.
  • Calcium carbonate exhibits pleomorphism, forming crystals of both calcite and aragonite.

Advanced Usage

• "Genetic pleomorphism": Refers to variations in form linked to genetic differences within a population.

  • The genetic pleomorphism in the insect population was linked to its rapid adaptation.

• "Pathological pleomorphism": Used in medicine, particularly histology, to describe significant variation in the size and shape of cells or nuclei, often associated with malignancy.

  • The pathologist noted marked nuclear pleomorphism in the tumor cells.

Variants and Related Words

• Pleomorphic (adj): Having the quality of pleomorphism; existing in various forms.

  • The virus is pleomorphic, lacking a consistent shape.

• Polymorphism (n): A related but broader term. In biology, it refers to the occurrence of different forms among members of a population or species. In materials science, it is synonymous with pleomorphism for crystalline solids.

  • Single nucleotide polymorphism is a common form of genetic variation.

Synonyms

• (Biology): Polymorphism, morphological variation.
• (Chemistry): Allotropy (specifically for elements), polymorphism.

Notes on Meaning

• The term is highly specialized to scientific contexts, primarily biology and chemistry.
• In biology, it can describe normal life cycle stages (e.g., a jellyfish's polyp and medusa forms) or abnormal cellular variation.
• In chemistry, it is a specific case of the more general term "polymorphism," which applies to any crystalline material.

Noun

1. (biology) the appearance of two or more distinctly different forms in the life cycle of some organisms
2. (chemistry) the existence of different kinds of crystal of the same chemical compound