question_answer

Which of the following is not the feature of DNA double helix?

A)  The backbone is constituted by sugar - phosphate and the base project outside

B)  A purine always pairs with pyrimidine

C)  The pitch of helix is \[3.4\text{ }nm\] and there are roughly 10 base pair in each turn

D)  Plane of one base pair stacks over the other in double helix