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Related to monozygous: Monozygotic twins, monozygous twin


 [mon″o-zi-got´ik; mon″o-zi´gus] (monozygous) pertaining to or derived from a single zygote (fertilized ovum); said of twins. See also dizygotic.
A, Monozygotic twinning. The single inner cell mass divides into two inner cell masses during the blastocyst stage. These twins have a single placenta and chorion, but each twin develops in its own amnion. B, Dizygotic twinning. Two ova are released during ovulation, and each is fertilized by a separate spermatozoon. The ova may implant near each other in the uterus, or they may be far apart. From McKinney et al., 2000.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

mon·o·zy·got·ic twins

twins resulting from one zygote that at an early stage of development separated into independently growing cell aggregations giving rise to two individuals of the same sex and identical genetic constitution.


Relating to a single germ or zygote, for example, monozygotic.
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References in periodicals archive ?
Note that the posterior probability of the monozygous carrier genotype (x = 11) being almost zero for each individual is not shown here.
Monozygous concordance rates for focal epilepsy (0.34) and febrile epilepsy (0.60) were also much higher than anticipated, he said.
Initial zygosity studies indicated a 99.9% probability that they were monozygous. Subsequent studies done on skin samples, however, indicated dizygosity; these findings were confirmed upon additional genetic analysis.
One such example (summarized in Tippet, 1984) is a case of a monozygous pair of male twins identical in chromosome markers, HLA, isozymes an d serum proteins, both XX/XY in the blood, but differing in other organs sampled such as skin and secretory tissues.
Individuals with at least one diabetic parent have a much higher incidence of NIDDM than those of similar body habitus who do not have a diabetic parent.[13] Several studies of twins suggest that NIDDM is highly concordant among monozygous and less concordant among dizygous twins, indicating that genetic factors play a major role in the etiology of NIDDM.
"You should treat all clones like you would treat all monozygous [identical] twins or triplets,".concludes Dr.
As the 2 boys grew older, however, their almost indistinguishable appearance strongly suggested that they might be identical, or monozygous, twins.
Two studies comparing monozygous and dizygous twins may be cited.
One study of 57 monozygous and 49 dizygous twin pairs reared apart and 90 nontwin siblings showed that impulsivity as assessed by a personality questionnaire was significantly correlated in the monozygous twins but not in the others.
However, in such cases the risks could not be quantified because the database did not differentiate between monozygous and dizygous twin pairs.