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Related to Heterozygotes: homozygous, Compound heterozygotes, Homozygotes


(hĕt'ərōzī`gōt): see geneticsgenetics,
scientific study of the mechanism of heredity. While Gregor Mendel first presented his findings on the statistical laws governing the transmission of certain traits from generation to generation in 1856, it was not until the discovery and detailed study of the
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a cell or organism having in its hereditary set (genotype) different forms (alleles) of a given gene.

A heterozygote is the result of the union of gametes of different genetic composition, each of which brings its own alleles to the zygote. For example, homozygous types AA and aa form gametes A and a respectively. The heterozygote obtained by the hybridization of AA and aa always forms mixed gametes (A and a). Crossing this type with itself or with the recessive parental type aa produces offspring of two types—phenotypic A and phenotypic a. The splitting of the heterozygote proceeds according to Mendel’s law. The preservation of the heterozygote is of significance in agriculture, since splitting often leads to the loss of valuable qualities. Almost all fruit trees are heterozygous; in order to avert splitting and the loss of valuable traits, they are bred by vegetative reproduction, apomixis, gynogenesis, or parthenogenesis.



An individual that has different alleles at one or more loci and therefore produces gametes of two or more different kinds with respect to their loci.
References in periodicals archive ?
Such a situation is highly conducive to inbreeding that would contribute to significant deficiency of heterozygotes with no evident loss of alleles in SE.
Furthermore, it appears that patients who are heterozygote C282Y/ H63D and C282Y/S65C are at increased risk of developing hemochromatosis phenotypically.
Which of the following diagnoses can be confused with a compound heterozygote involving [HbD.
A] mRNAs in heterozygotes are balanced (around 50% of each one) but it is not so for the relative percentage of blood hemoglobin proteins (36), as was observed in the present case which had 55.
G707>C, C710>T, T761>C known substitutions in exon 6 were defined in both heterozygote and homozygote types.
4) A 50 per cent reduction in the excretion of 5-OH-OPZ was expected in CYP2C19 heterozygotes compared to normal homozygotes on the basis of gene dose phenomenon (32) but heterozygotes demonstrated only 35 per cent decreased excretion of 5-OH-OPZ.
Allozyme genetic studies of bivalves have often revealed significant deficiencies of heterozygotes relative to the Hardy-Weinberg model and a number of explanations were proposed such as selection, the Wahlund effect, inbreeding and null alleles where the presence of nonfunctional protein product confuses the scoring of heterozygotes and homozygotes (Gaffney 1994).
In each generation, plants heterozygotes for 1-22 or 1-23 were identified by GISH.
andium, born in captivity and direct descendants of animals collected two years before in the same locality, had a litter of three pups, where one of them was an albino female, proving that both specimens were heterozygotes for the albino allele.