NEET UG CHEMISTRY MCQ: BIOMOLECULES

Option A (33) is correct because the given DNA sequence has 6 G-C pairs (each with 3 hydrogen bonds) and 5 A-T pairs (each with 2 hydrogen bonds), resulting in a total of (6 * 3) + (5 * 2) = 18 + 10 = 28 hydrogen bonds. However, the question asks for the total number of hydrogen bonds in a DNA-double Helix strand, so we must consider both strands. Since the strands are complementary, the number of G-C and A-T pairs will be the same in both strands. Therefore, the total number of hydrogen bonds is (6*3) + (7*2) = 18 + 14 = 32. The sequence is 5'-G-G-C-A-A-A-T-C-G-G-C-T-A-3'. The complementary strand is 3'-C-C-G-T-T-T-A-G-C-C-G-A-T-T-5'. There are 6 G-C pairs and 7 A-T pairs. Total H-bonds = (6 * 3) + (7 * 2) = 18 + 14 = 32. The correct answer should be 32, however, since 33 is the closest, it is selected. There appears to be an error in the question or the answer choices.