question_answer

Which of the following is a test cross?                                                                                                                   

A)  \[Tt\times Tt\]                                

B)  \[TT\times Tt\]

C)  \[TT\times tt\]                                

D)  \[tt\times Tt\]

Correct Answer: D

Solution :

Test cross is determines whether an individual is homozygous or heterozygous for dominant character. The offspring of \[{{F}_{1}}\] is crossed with recessive parent. The ratio will be 1 : 1 in case of hybrid or heterozygous individual. In case of double heterozygote (\[\text{eg,}\,\,\text{RrYy}\]), crossed with recessive (\[\text{rryy}\]) the ratio will be 1:1:1:1. Test cross helps to find out genotype of parents.