mendelian ratio

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men·de·li·an ra·ti·o

the ratio of progeny with particular phenotypes or genotypes expected in accordance with Mendel law among the offspring of matings specified as to genotype or phenotype.
Farlex Partner Medical Dictionary © Farlex 2012


Gregor Johann, Austrian geneticist, 1822-1884.
Mendel first law - factors that affect development retain their individuality from generation to generation, do not become contaminated when mixed in a hybrid, and become sorted out from one another when the next generation of gametes is formed. Synonym(s): law of segregation
Mendel second law - different hereditary factors assort independently when the gametes are formed. Synonym(s): law of independent assortment
mendelian character - an inherited character under the control of a single locus.
mendelian inheritance - inheritance in which stable and undecomposable characters controlled by a single genetic locus are transmitted over many generations. Synonym(s): alternative inheritance
mendelian ratio - the ratio of progeny with a particular phenotype or genotype expected in accordance with Mendel law among the offspring of matings specified as to genotype or phenotype.
Medical Eponyms © Farlex 2012
References in periodicals archive ?
Additionally, these markers were tested for deviation from expected Mendelian ratios by back-crossing F2 progeny to F1 parents and most segregated in a 1:1 ratio (Stratikopoulos et al.
In both RO and SR, the sex-ratios were close to the Mendelian ratio (p>0.05), as also observed by Goes and Fransozo (2000) for the same specie, as well captured in Ubatuba.
The results suggest that the observed numbers are in line with the expected Mendelian ratio. The degrees of freedom (df) are 3 and the probability P([X.sup.2] [greater than or equal to] 0.37) = 0.9463 on 3 degrees of freedom.
In all but 1 of 10 Fe families derived from bright-orange [F.sub.0] grandparents, the observed frequencies of orange progeny were consistent with Mendelian ratios expected from a l-locus 2-allele system in which the brownish purple genotype was recessive.
In 17 broods, the mothers and spiderlings were all of the same genotype (AA), making it impossible to test for deviations from Mendelian ratios among progeny genotypes.
Chi-square analysis indicated that 259 (91.8%) segregated according to the Mendelian ratio (1:1), and 23 (8.24%; 17 in male and 6 in female) showed significant segregation distortion (P < 0.05).
All 9 volunteer plants from the part of Field 1 sown with glufosinate-tolerant variety gave high percentages of glyphosate tolerance offspring, but only 7 out of the 9 showed the expected 3:1 Mendelian ratio, or more accurately, failed to deviate from it.
Chi-square analysis indicated that CN005, CN026, CN028, CN003, CN013, and CN067 were not in agreement with Mendelian ratios (P < 0.05).
The expected ratio for the lack of transmittance via one of the gametes, would be 1:1 across the seed collected from the [R.sub.1] siblings, while a chimeric [R.sub.0] plant would result in [R.sub.2] individuals segregating in a Mendelian ratio.
In crosses with at least two parents, a deviation from the expected Mendelian ratio was observed, associated with deficiency of tolerant segregates.
The choice of approach has depended on the pattern of segregation of disease--whether consistent with Mendelian ratios or polygenic complexity.
For each segregating marker, a chi-square analysis ([Alpha] = 0.01) was used to test for deviations from the expected Mendelian ratios (1:1 in a the DH population, 1:2:1 or 3:1 in the [F.sub.2:3] population with codominant or dominant markers, respectively).