Question

$1:1:1:1$ ratio of progenies can be obtained if the plants employed for crossing are
A. TTRR $\times$ ttRR
B. TtRr $\times$ ttrr
C. TtRR $\times$ ttrr
D. Ttrr $\times \mathrm{ttRr}$

• A. $\text{A, C and D}$
• B. $\text{A, B, C and D}$
• C. $\text{B and D}$
• D. $\text{A and B}$

Answer 1

Answer: (C)

$\text{1:1:1:1}$ is a dihybrid test cross ratio. It is obtained when crossing is done between a hybrid and a recessive genotype, when two gene loci are considered simultaneously.