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germ plasm

From Wiktionary, the free dictionary
See also: germplasm and germ-plasm

English

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Alternative forms

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Etymology

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Calque of German Keimplasma. From circa 1892.

Noun

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germ plasm (uncountable)

  1. (biology, dated or historical) The cytoplasm of germ cells.
    • 1893, August Weismann, translated by W. Newton Parker and Harriet Rönnfeldt, The Germ-plasm: A Theory of Heredity, Charles Scribner's Sons, page 183:
      If heredity depends on the presence of a substance, the germ-plasm, which causes the production of the new individual by directing the process of division in ontogeny, in the course of which it becomes changed in a regular manner, the question arises as to how unaltered germ-plasm can nevertheless reappear in the germ-cells of the new individual.
    • 1951, Bradley M. Patten, Early Embryology of the Chick, 4th edition, The Blakiston Company, page 10:
      The germ plasm is of paramount interest, not only to the biologist but to all thinking persons, because while the somatic cells cease to exist with the death of the individual whose body they constitute, the germ plasm may live on indefinitely in succeeding generations.
    • 2006, Matt Wray, Not Quite White, page 107:
      The eugenics movement […] placed the blame squarely on the degenerative germ plasm passed down from generation to generation, corrupting entire bloodlines.
    • 2014, Eva Jablonka, Marion J. Lamb, Evolution in Four Dimensions, The MIT Press (Bradford Books), page 19,
    He[Weismann] reasoned that since the father's germ plasm in the sperm mixes with the mother's germ plasm in the egg, there are two mingled germ plasms in their offspring.
    Synonym: pole plasm
  2. Germplasm; seeds or tissues maintained for the purpose of animal or plant breeding, preservation or other research uses.
    • 1976, Te-Tzu Chang, Manual on Genetic Conservation of Rice Germ Plasm for Evaluation and Utilization, International Rice Research Institute, page 56:
      Although the IRRI has taken on the global responsibility of conserving rice germ plasm, we find it necessary to enlist the collaboration of other international and national organizations in achieving the goals.

Usage notes

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  • The biology term relates to the obsolete germ plasm theory (Keimplasmatheorie), described in 1892 by German biologist August Weismann. Through his theory he rejected Lamarckism and proposed what came to be called the Weismann barrier: the principle that germ cells can influence somatic cells, but not vice versa. Weismann's theory was made obsolete by genetics, but the idea that changes acquired during an organism's life cannot affect its offspring is still broadly accepted, albeit within a framework of epigenetic variable expression contrasting with mendelian heredity.

Translations

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Further reading

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