Question

Test cross involves

(a) crossing between two genotypes with recessive trait 

(b) crossing between two F₁ hybrids 

(c) crossing the F₁ hybrid with a double recessive genotype 

(d) crossing between two genotypes with dominant trait

Answer 1

Correct option (c) crossing the F₁ hybrid with a double recessive genotype

Explanation

The test cross involves the crossing of F₁ 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.