Question

Test cross involves
A. crossing between two genotypes with recessive trait
B. crossing between two `F_(1)` hybrids
C. crossing the `F_(1)` hybrid with a double recessive genotype
D. crossing between two genotypes with dominant trait

Answer 1

Correct Answer - C
The test cross involves the crossing of `F_(1)` hybrid with a double recessive genotypic parent. By test cross, the heterozygosity and homozygosity of the organism can be tested.
Thus, the offspring will be 100% dominant, if the individual which crossed with recessive parent, i.e. (tt) was homozygous dominant and ratio will be 50% dominant and 50% recessive if the individual was heterozygous dominant. In dihybrid test cross, ratio will be 1:1:1:1.