Structure of DNA

DNA is a double helix spiral of polymer strands made up of nucleotides. The strands are bonded by weak hydrogen bonds at the complementary base pairs. 

Each nucleotide is made up of three things:

• a sugar molecule (dioxyribose)
• a phospate molecule
• a base (A,T, C or G)

Complementary base pairs:

• A(denine) and T(hymine) (Apple and Tree)
• C(ytosine) and G(uanine) (Carrot and Garden)

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