question_answer

                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

Correct Answer: C

Solution :

                The test cross involves the crossing of \[{{F}_{1}}\] 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 was heterozygous dominant. In dihybrid test cross, ratio will be 1 : 1 : 1 : 1.