List out the salient features of double helix model of DNA.

Explanation

Salient features of the double helix structure of DNA are as follows.
DNA is made up of two poly nucleotide chains, where the back bone is constituted by sugar-phosphate and the bases projeets inside.
The two chains have anti parallel polarity. It means one chain has the polarity `5.rarr3.` and the other has `3.rarr5.`.
The bases in the two strands are paired through hydrogen bond forming base pairs.
The bases show complementary base pairing Adenine always pairs with thymine with double bonds and Guanine pairs with cytosine with triple bonds. The two strands are coiled in a right handed fashion, the pitch of the helix is 3.4nm and there are 10 base pair in each turn.
The distance between a base pair in a helix is 0.34nm. And the diameter of the DNA molecule is 20nm.
The plane of one base pair stacks over the other in double helix. This confirms stability of the helical structure.
The double helix has two grooves i.e major groove and a minor groove.