Testcross | definition of testcross by Medical dictionary
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Related to testcross: incomplete dominance
Crossing of an unknown genotype to a recessive homozygote so that the phenotype of the progeny corresponds directly to the chromosomes carried by the parents of unknown genotype.
testcross (tĕst′krôs′, -krŏs′)
A cross between an individual exhibiting the dominant phenotype of a trait and an individual that is homozygous recessive for that trait in order to determine the genotype of the dominant individual.
To subject to a testcross.
Etymology: L, testum + crux, cross
1 a cross between a dominant and a recessive phenotype to determine either the degree of genetic linkage or whether the dominant phenotype is a result of a homozygous or a heterozygous genotype.
a subject undergoing such a test. See also backcross
Fig. 295 Testcross. A testcross to find the genotype of the unknown parent.
testcross a cross in which one partner is homozygous (see HOMOZYGOTE for the recessive alleles of the genes being investigated. The testcross progeny will indicate the GENOTYPE of the unknown parent. See Fig. 295 . Test crosses are used extensively in experiments to establish GENETIC LINKAGE. See also BACKCROSS.
References in periodicals archive
18] / Y males to produce the testcross diagrammed in Figure 2B.
The following will describe the three point testcross exercises in detail; however, the dihybrid testcrosses (see above) are identical except for replacing [y.
These F1 flies were either mated together to produce dihybrid F2 data or were testcrossed to produce dihybrid testcross data.
The F1 male testcross shows that no recombinants are produced by the male F1.