JEE Advanced levelNumerical answerDifficulty 3 of 3bm207
A DNA duplex has one strand 5-prime ATGCGCATTAGC 3-prime paired with its complementary antiparallel strand. Count two hydrogen bonds for each A-T pair and three for each G-C pair. The total number of hydrogen bonds holding the duplex together is (integer)
Numerical answer type, tolerance 0.5.
Answer: 30
The sequence has 6 A/T bases and 6 G/C bases, so there are 6 A-T pairs and 6 G-C pairs. H bonds = 6 x 2 + 6 x 3 = 12 + 18 = 30.