Question

Test cross involves

• A. crossing between two genotypes with recessive trait
• B. crossing between two F, hybrids
• C. crossing the $F_1$ hybrid with a double recessive genotype
• D. crossing between two genotypes with dominant trait

Answer 1

Answer: (C)

The test cross involves the crossing of F, hybrid with a double, recessive genotypic parent. By test cross, the heterozygocity and homozygocity 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 1 was heterozygous dominant. In dihybrid test cross, ratio will be 1:1:1:1.