Explain the DNA structure in details?

Structure :  Each DNA molecule is a double stranded polymer, consisting of perhaps thousands or millions of linked nucleotides. The two long strands of DNA twist around the central axis to form a double helix. The structure of the double helix was elucidated using X-ray diffraction and model building by Watson and Crick, along with Rosalind Franklin, Maurice Wilkins and others.

The model developed by this group, proposed in 1953, is called the central dogma of molecular biology, and is one of the most significant biological discoveries ever.

The two strands of DNA in the double helix are held together by hydrogen bonds between adjacent base pairs. These base pairs form what is sometimes referred to as the "rungs" of the DNA ladder, if the helix could be uncoiled. Adenine always bonds with thymine; guanine always bonds with cytosine.

The amount of adenine in a cell, therefore, is always the same as that of thymine, and the amount of guanine the same as that of cytosine. Adenine and thymine form two hydrogen bonds between themselves; guanine and cytosine form three hydrogen bonds between themselves. Because of this bonding, each strand has a base sequence which is the exact complement of the sequence on the adjacent strands.