BACK CROSS
DEFINITION :- It is a genetic cross between a hybrid organism and one of the original parental types is called back cross.
EXAMPLE OF BACK CROSS:-
A monohybrid cross between a homozygous black guinea pig and homozygous white guinea pig gives F1 generation of heterozygous black offspring. The back cross between the F1 heterozygous black individual and the homozygous black parent will produce black guinea pig only.
RESULT OF A BACK CROSS
The result of the back cross depends on the parental type. A back cross between a heterozygous F1 individual and a homozygous dominant parent gives the progeny having the dominant trait only as in the above figure shows.
On the other hand,, a back cross between F1 heterozygous and a homozygous recessive parent produces offspring with both the genotype as described in test cross.
USE OF BACK CROSS
The back cross is used by the plant and animal breeders as a rapid method of purifying the desired stock.