Test cross
Encyclopedia
In genetics
, a test cross, first introduced by Gregor Mendel
, is used to determine if an individual exhibiting a dominant trait is homozygous or heterozygous for that trait. Put more simply test crosses determine the genotype of an individual with a dominant phenotype.
Test crosses involve breeding the individual in question with another individual that expresses a recessive
version of the same trait. If all offspring
display the dominant phenotype, the individual in question is homozygous dominant; if the offspring display both dominant and recessive phenotypes, then the individual is heterozygous.
In some sources, the "test cross" is defined as being a type of backcross
between the recessive homozygote and F1 generation or F2 generation crossed with recessive parent is said to be a test cross.
If the individual being tested produces any recessive offspring (except in cases of incomplete penetrance) its genotype is heterozygous. If all the offspring are phenotypically dominant, its genotype is homozygous.
for other crosses look for Di-hybrid and mono-hybrid crosses, these can provide more accurate and more detailed information on genotypes behind phenotypes in organisms.
Definition:
Mendel devised a cross which is used to test the genotype of an individual showing a dominant phenotype. it is a mating in which an individual showing an dominant phenotype is cross with an individual showing its recessive phenotype.
Genetics
Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....
, a test cross, first introduced by Gregor Mendel
Gregor Mendel
Gregor Johann Mendel was an Austrian scientist and Augustinian friar who gained posthumous fame as the founder of the new science of genetics. Mendel demonstrated that the inheritance of certain traits in pea plants follows particular patterns, now referred to as the laws of Mendelian inheritance...
, is used to determine if an individual exhibiting a dominant trait is homozygous or heterozygous for that trait. Put more simply test crosses determine the genotype of an individual with a dominant phenotype.
Test crosses involve breeding the individual in question with another individual that expresses a recessive
Recessive
In genetics, the term "recessive gene" refers to an allele that causes a phenotype that is only seen in a homozygous genotype and never in a heterozygous genotype. Every person has two copies of every gene on autosomal chromosomes, one from mother and one from father...
version of the same trait. If all offspring
Offspring
In biology, offspring is the product of reproduction, of a new organism produced by one or more parents.Collective offspring may be known as a brood or progeny in a more general way...
display the dominant phenotype, the individual in question is homozygous dominant; if the offspring display both dominant and recessive phenotypes, then the individual is heterozygous.
In some sources, the "test cross" is defined as being a type of backcross
Backcrossing
Backcrossing is a crossing of a hybrid with one of its parents or an individual genetically similar to its parent, in order to achieve offspring with a genetic identity which is closer to that of the parent...
between the recessive homozygote and F1 generation or F2 generation crossed with recessive parent is said to be a test cross.
If the individual being tested produces any recessive offspring (except in cases of incomplete penetrance) its genotype is heterozygous. If all the offspring are phenotypically dominant, its genotype is homozygous.
for other crosses look for Di-hybrid and mono-hybrid crosses, these can provide more accurate and more detailed information on genotypes behind phenotypes in organisms.
Definition:
Mendel devised a cross which is used to test the genotype of an individual showing a dominant phenotype. it is a mating in which an individual showing an dominant phenotype is cross with an individual showing its recessive phenotype.