Question
Write a note on Double Helical structure of DNA.

Answer

Information regarding the sequence of nucleotides in the chain of a nucleic acid is called its primary structure. Nucleic acids have a secondary structure too.
James Watson and Francis Crick gave a double strand helix structure for DNA. Two nucleic acid chains are wound about each other and held together by hydrogen bonds are formed between specific pairs of bases. Adenine forms hydrogen bonds with thymine where as cytosine forms hydrogen bonds with guanine.
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