KVPY 2019 SB SX Exam Previous Papers

A newly discovered organism possesses a gentic material with a new base composition consisting of the sugar and phosphate backbone as found in existing natural DNA. The five novel bases in this gentic material-namely, P, Q, R, S, T – are heterocyclic structures with 1, 1, 2, 2 and 3 rings, respectively.
Assuming the new DNA forms a double helix of uniform width, which one of the following would be the most appropriate base pairing?