Draw only labelled diagram of a DNA double helix structure.
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Solution and Explanation
A labelled diagram of the DNA double helix structure is as follows: 
Key Features of the DNA Double Helix Structure:
1. **Double Strands**: DNA consists of two long chains of nucleotides coiled around each other, forming a double helix structure.
2. **Sugar-Phosphate Backbone**: The backbone of each strand is made up of alternating sugar (deoxyribose) and phosphate groups.
3. **Nitrogenous Bases**: Each strand contains nitrogenous bases (Adenine, Thymine, Cytosine, Guanine) that pair specifically:
- Adenine (A) pairs with Thymine (T) via two hydrogen bonds.
- Cytosine (C) pairs with Guanine (G) via three hydrogen bonds.
4. **Complementary Base Pairing**: The two strands of DNA are complementary, meaning the sequence of bases on one strand dictates the sequence on the other strand.
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