GENETICS AND EVOLUTION
GENETIC BASIS OF INHERITANCE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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A cross between organisms of the same generation
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A cross between an organism of recessive phenotype and another organism of dominant phenotype but of unknown genotype
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A cross between an organism of dominant phenotype and another organism of dominant phenotype but of unknown genotype.
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None of the above
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Detailed explanation-1: -The test cross is another fundamental tool devised by Gregor Mendel . In its simplest form, a test cross is an experimental cross of an individual organism of dominant phenotype but unknown genotype and an organism with a homozygous recessive genotype (and phenotype).
Detailed explanation-2: -testcross, the mating of an organism whose genetic constitution is unknown with an organism whose entire genetic makeup for a trait is known, to determine which genes are carried by the former.
Detailed explanation-3: -A cross in which an organism showing a dominant phenotype is crossed with the recessive parent in order to know its genotype is called a test cross.
Detailed explanation-4: -The unknown genotype can be determined by observing the phenotypes of the resulting offspring. If crossing the unknown dominant phenotype (PP or Pp genotype) individual with the recessive phenotype individual produces only dominant phenotypes (no recessive), then the unknown individual is homozygous dominant.