Given below are two statements: Statement I: In a B-DNA double helix, the pitch of the helix is 0.34 nm and the distance between two consecutive base pairs is 3.4 nm . Statement II: The two chains of a DNA double helix have anti-parallel polarity, meaning if one chain has the polarity 5' 3' , the other has 3' 5' . In the light of the above statements, choose the correct answer from the options given below:

Step-by-step solution

Statement I is incorrect because in a B-DNA double helix, the pitch of the helix is 3.4 nm and the distance between two consecutive base pairs is 0.34 nm . The values given in the statement are interchanged. Statement II is correct because the two chains of a DNA double helix are anti-parallel, meaning one chain runs in the 5' 3' direction and the other runs in the 3' 5' direction. Therefore, Statement I is incorrect but Statement II is true. Answer: Statement I is incorrect but Statement II is true.