Question

With the help of clear and labelled diagrams explain the molecular structure of DNA.

Answer 1

DNA is a double helix structure. it was discovered by two scientists James Watson and Francis Crick.
the four nitrogenous bases are :
adenine
thiamine
guanine
cytosine

Answer 2

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Explanation →_→

Each strand of DNA is composed of nucleotides which are made up of three components phosphate , sugar and nitrogenous base. The four types of nitrogenous bases are thymine , adenine , guanine and cytosine