from The American Heritage® Dictionary of the English Language, 4th Edition

  • adj. Derived from a single fertilized ovum or embryonic cell mass. Used especially of identical twins.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • adj. That has developed from a single fertilized ovum

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • adj. derived from a single fertilized egg


Sorry, no etymologies found.


  • Of 5,597 monozygotic twin pairs where both were alive and had provided usable responses to CFS screening questions, we identified 140 pairs of twins who met preliminary inclusion criteria: born 1935-1985, classified as a monozygotic twin based on questionnaire responses

    PLoS ONE Alerts: New Articles

  • Therefore although I might call them "monozygotic" I wouldn't agree that they were "identical."

    Identical Boy-Girl Twins

  • In "A Genetic Study of Male Sexual Orientation," a study that has now achieved almost as much renown as LeVay's, the Northwestern University psychologist Michael Bailey and Boston University's Richard Pillard compared fifty-six "monozygotic" twins (identical twins, from the same zygote, or fertilized egg), fifty-four "dizygotic" (fraternal) twins, and fifty-seven genetically unrelated adopted brothers.

    Homosexuality and Biology

  • Classical liberals (libertarians, basically) accept that only monozygotic twins are “created equal” and that even these will diverge as they mature.

    The Volokh Conspiracy » 4. On a Bus in Kiev

  • But births of monozygotic twins are rare, roughly one in 300.

    Separated At Birth. Really.

  • The mother assumed that she had given birth to fraternal twins (dizygotic, from two eggs) and not "identical" ones (monozygotic, two embryos developed from a single fertilized egg).

    Separated At Birth. Really.

  • In the switched-baby cases Ms. Segal discusses, it is highly unlikely that the error would have been discovered were it not for the fact that the twins were monozygotic and thus had a striking physical resemblance.

    Separated At Birth. Really.

  • And most of us have probably ingested meat and dairy products from livestock cloned by natural reproduction (monozygotic siblings), mechanical embryo-splitting or even nuclear transfer from an embryonic donor cell into an enucleated oocyte.

    The Cloned Cow Has Left the Barn

  • In contrast, we present here evidence for cognitive “specialist genes”: monozygotic twins are more similar than dizygotic twins in the specific cognitive ability of face perception. Blog Articles » Print » Is Facial Recognition A Non-g Factor Mental Module?

  • Each of three measures of face-specific processing was heritable, i.e., more correlated in monozygotic than dizygotic twins: face-specific recognition ability, the face-inversion effect [2], and the composite-face effect [3]. Blog Articles » Print » Is Facial Recognition A Non-g Factor Mental Module?


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