The Watson and Crick structure of DNA (B-DNA) has following features:-

1)  It consists of two antiparallel polynucleotide strands that wind about a common axis with a right handed twist to form a double helix.

2)  The diameter of a double helix will be around 20 Å.

3) Each base is hydrogen bonded to a base on opposite strand (A with T and G with C) to form a planar base pair and the planes of these base pairs are nearly perpendicular to the helix axis.

4)  The ideal B DNA helix has 10 base pairs per turn and the helix rotates 36° per base pair.

5)  The helix has a pitch (the distance raised by common axis in a complete turn) of 34 Å so the per base pair raise in common axis will be 3.4 Å.

6)  The double helix has major and minor grooves.