The reason for double helical structure of $DNA$ is operation of
Van der Waals' forces
Dipole -dipole interaction
Hydrogen bonding
Electrostatic attractions
Purines found both in $DNA$ and $RNA$ are
Which of the following is correct for Watson and Crick's model of $DNA$. It is duplex with
In the $340 A^o$ long $DNA$ strand
Which one of the following pairs of nitrogenous bases of nucleic acids, is wrongly matched with the category mentioned against it ?
One turn of $DNA$ possesses